The five young (and not-so-young!) players all made an impression on th

e 2018 Diamondbacks. Who was the best?"Yoshihisa Hirano While not the first Japanese-born pitcher to play for the Diamondbacks Randal Grichuk Jersey , there’s no doubt Hirano is the best. His ERA+ of 178 was the best by any rookie-eligible reliever (min 60 IP) for the Diamondbacks since Oscar Villarreal’s 182 in 2003. Hirano went almost two months without allowing a run. From May 6-July 3, he set a franchise record with 26 consecutive scoreless appearances, covering 22.2 innings, breaking the old mark of 24 games (J.J. Putz in 2012 + Brandon Lyon in 2008). Hirano finished the season as the D-backs’ closer, taking over from Brad Boxberger. In the 2010’s, only Jake Barrett in 2016 has had more rookie saves for Arizona. Hirano was especially adept at rolling up the double-play, with his 14 ranking second on the team, behind only...Matt KochYou’d be forgiven for writing Koch off after he posted a literally infinite ERA in 2017, allowing three runs without retiring a batter. But he bounced back with a solid season, giving Arizona a much-needed 14 starts, taking over in the rotation after Taijuan Walker required Tommy John surgery. Six of those were quality starts, likely peaking with the outing shown above, where Koch tossed seven shutout innings of three-hit ball, walking none and striking out six, retiring 17 of the last 18 batters faced. Helped by all those double-plays, efficiency was Koch’s keyword: his average of 3.60 P/PA was best in the team by a pitcher. Those seven innings versus the Marlins needed only 84 pitches. Jimmie SherfyOver his first 26 regular-season appearances, Sherfy has a 1.00 ERA. That’s the best in franchise history, just edging out Doug Slaten’s 1.06 from 2006-07. This season, he made fifteen appearances, and was scored up in just two, striking out more than a batter per inning (17 in 16.1 IP). Sherfy was particularly good as a September call-up. That month Jose Bautista Jersey , he ha a 1.46 ERA, holding batters to a .143 average (6-for-42), with 14 K’s over 12.1 innings. His best game was probably at Coors Field on September 13, where he struck out four over two innings of scoreless relief. A bullpen spot seems assured for 2019, and he seems likely to see higher-leverage situations, and perhaps even save opportunities. Ildemaro VargasDespite making his MLB debut in June 2017, Vargas had to wait until rosters expanded in September before getting the call this season. He was initially put in the tough spot of pinch-hitting, but fared considerably better as a starter (3-for-7 with a home-run) than off the bench (1-for-12). He lived up to his reputation for putting the ball in play, not striking out at all over his last seven games, hitting .308 over that spell. Ildemaro saved the best for almost-last. He hit his first major-league home-run and drove in three key runs in Arizona’s penultimate game of the season, a 5-4 victory over the Padres in San Diego, and was rewarded the following day with the ol’ “bubble-gum on the cap” routine. Christian WalkerWalker is among the team’s best pinch-hitters of all-time. Among those with 10 or more PA this season, only Ketel Marte has a higher OPS in those situations than Christian’s .723. He was also the only Diamondback this year with more than one home-run in that role. Most remarkable of all, both of those came off the Dodgers’ Clayton Kershaw, the first, on May 1 (above), was among the longest in franchise history, then Walker had another four months to the day later. Over the past decade, no Diamondback has hit more homers than Walker as a pinch-hitter - even though he didn’t make his debut until 2017. In team history, among the 53 men with 35+ PA as a PH, only Chad Tracy has a higher OPS than Christian. Here’s the poll. We have had... issues in the past with this category http://www.bluejaysfanproshop.com/authentic-curtis-granderson-jersey , so I reserve the right to declare the whole thing null and void, in the event of Florida-like shenanigans! Hint: it’s not as impressive as you think."The Detroit Tigers aren’t doing anything right now, and it’s hard to blame them. While they still have a few things they need to address this offseason, it’s only January 7. There are still nearly six weeks until spring training, and 80 days until the regular season begins. We’re impatient, of course, but we are fans. We’re irrational.Despite the lack of news, we still have plenty of things to talk about when it comes to our favorite baseball team. Not only have we been busy breaking down what we want to see from the Tigers this year, we’re also knee-deep in our 2019 prospect profiles.Best of all, the fanbase’s appetite for Tigers news and coverage is still present. We received several great questions for this latest Tigers mailbag, as well as a few more ideas for things to tackle before we get into our normal season preview coverage.Also, a special shoutout to our Facebook commenters who came through in a big way for questions this week. Step your game up, Twitter.Spoiler alert: it’s not as much as you think. My initial guess is that Castellanos could maybe net the Tigers a back-end top-100 prospect, or a couple of lower-tier prospects.Luckily for me, someone else already did the hard work:That’s MaxG over at Max’s Sporting Studio, a new site I’m going to be checking in on frequently. Max took FanGraphs’ recent work on prospect valuation and applied it to Castellanos’ trade value to estimate a potential return for the Tigers’ right fielder.Taking Bryce Harper off the market might incentivize teams to pay a bit more for Castellanos, but don’t expect much more than the above return. Allard, for example, ranks as MLB Pipeline’s No. 100 prospect right now, and Muller is a couple of spots behind him on their Braves rankings.Personally, I wouldn’t mind seeing the Tigers take a risk with the compensatory round pick they will receive for Castellanos next offseason. That prospect might not be quite as good as Allard or Muller Marcus Stroman Jersey , but it would (a) give them another season of Castellanos’ bat, and (b) give them another 10 months to potentially work out a contract extension.From Jay Matthews on Facebook: Who do you think will be in the TV booth for the Tigers in the upcoming season?As many of us expected, the Tigers are sticking with Kirk Gibson and Jack Morris as the primary analysts on Fox Sports Detroit broadcasts in 2019. Gibson did most of the games after Mario Impemba and Rod Allen were suspended last fall, and seems to have a good rapport with potential play-by-play men Matt Shepard and Dan Dickerson. Morris splits his time between the Tigers and Minnesota Twins, but is also familiar with how Fox Sports Detroit runs things.(They’re also still under contract, which was probably the biggest reason they are sticking around.)As for the team’s new play-by-play man? That’s anyone’s guess. Potterville native Joe Davis has already turned down the gig, and for good reason; he is Vin Scully’s hand-picked replacement in Los Angeles, and has already laid down roots with his young family out west. Pirates announcer Joe Block is another longshot despite ties to the area. Former Tigers announcer Josh Lewin is also out of the running.While the Tigers and Fox Sports Detroit have mentioned they are casting a nation-wide net in search of their next announcer, my guess is they end up with someone already in the organization. That could be as simple as taking the “interim” tag off Matt Shepard, or bringing Dickerson over to the TV side after years of calling games on the radio. Minor league announcers Greg Garnia or (our pick) Dan Hasty could also be in the mix for either TV or radio, depending on where Dickerson ends up.From Rob Adams on Facebook: Can Candelario play first, Miggy DH, and sign Mike Moustakas?I’m always in favor of the Tigers trying weird things, and I love this idea. Moustakas had a decent season splitting time between the Kansas City Royals and Milwaukee Brewers, but his bat took a step back from the 118 OPS+ he posted between 2015 and 2017, when he was a two-time All-Star. If the Tigers were able to land him on a one-year deal, he could potentially rebuild value and net the Tigers a prospect at the July trade deadline. He would almost certainly be a bigger upgrade than any first baseman the Tigers could add to give Miguel Cabrera more days off his feet during the season.Unfortunately, I don’t think either side wants this to happen. Moustakas will be seeking as big of a contract as possible, and all things considered, would likely prefer to land with a contender (a reunion with the Brewers isn’t out of the question). The Tigers are being cost-conscious right now, to put it nicely Devon Travis Jersey , and likely won’t be out-bidding anyone for a premium free agent.They also won’t want to move Candelario away from third base until it’s absolutely necessary. Candelario had his issues at the plate during a second half swoon, but managed a respectable -1 Defensive Runs Saved (DRS) and +3.2 Ultimate Zone Rating (UZR) in over 1,200 innings at the hot corner last year. He is a capable defender over there, and will not be moved unless it’s to make room for a long-term solution.From Brian Sprung on Facebook: Will we see Mize, Manning or Perez up this year or will we have to wait until 2020?Let’s get the easy one out of the way; there is almost zero chance we see Matt Manning in Detroit in 2019. He fanned a few batters in his two starts at Double-A to close out the 2018 season, but he still has a long way to go developmentally until he is ready to face major league hitters. Expect him to spend all of 2019 at Double-A, and most of 2020 in the minors as well.From there, it gets interesting. Casey Mize is the most advanced of these three prospects, and will probably be the one competing for a spot in the Tigers’ starting rotation in 2020. He should make it to Double-A very quickly this year (if he doesn’t just start the season there) and might make his way up to Triple-A soon after if things go well. He has the four-pitch mix and the advanced command to make life hell for minor league hitters. FanGraphs’ Kiley McDaniel recently predicted that Mize would likely make it to Detroit by season’s end.But if I’m going to bet on someone making it first, it might actually be Franklin Perez. He holds a big advantage over Mize and Manning in that he is already on the 40-man roster, and was well ahead of the other two heading into the 2018 season. Were it not for his lat and shoulder injuries, he would likely be on the doorstep of the majors right now. Getting back to full health and simply logging a bunch of innings will be Priority No. 1 for Perez and the Tigers in 2019, but there is little reason for them to hold him back when calling players up in September. Meanwhile, keeping Mize down in the minors not only helps them game his service time, it also keeps a spot on the 40-man roster open for next offseason. So while Mize might be the most MLB ready by season’s end, my guess is Perez gets there first.