The Tigers’ Approach to Rotation Depth

They’re called five-man rotations, yet virtually no teams make it through 162 games without relying on more than five starters. There are exceptions, as the 2003 Mariners proved, but on average MLB teams have used 9.9 starters each over the course of the past five years.

That’s why teams sign “depth” starters every offseason and it’s why the Tigers’ current approach stands out. Their front five looks good; Justin Verlander, Max Scherzer, Rick Porcello, Phil Coke and Brad Penny promise to keep the Tigers in enough games to make them contenders for the AL Central title. But unlike other teams, the Tigers aren’t stocking up on rotation depth — at least for now.

It’s especially noteworthy since Penny missed most of 2010 with a shoulder strain and that Coke has started exactly one big-league game. Though the left-hander started 77 games in the Yankees’ minor league system and  manager Jim Leyland and GM Dave Dombrowski are showing lots of confidence in Coke, he is far from a proven MLB starter.

Some clubs, including Coke’s former team and the Cubs, have loaded up on non-roster invitees with years upon years of experience in the majors. The Tigers’ invitees? They have combined to start all of 30 big-league games.

There’s more to depth than big leaguers, of course, and the Tigers’ system features a number of promising power arms, including an unusually deep group of young left-handers. Andy Oliver could be ready for a big-league role at some point in 2011, though he struggled through his first five big-league starts last summer and the Tigers have said they would prefer not to rush him. While southpaws Duane Below and Charlie Furbush could see the majors this year, it’s hard to imagine Jacob Turner, Drew Smyly or Casey Crosby contributing just yet.

When you consider that most teams rely on ten starters over the course of a season and realize that Oliver, who struggled in the majors, Furbush, who has spent one season above Class A and Below, who hasn’t reached Triple-A, are the Tigers’ next line of defense, it’s apparent that Detroit doesn’t have much depth behind its potentially formidable front five.

Compare the Tigers’ depth to a team like the Red Sox, who don’t have room for Tim Wakefield, Felix Doubront, Alfredo Aceves, Andrew Miller or Junichi Tazawa in their rotation. Or the Reds, who will rely on Mike Leake, Travis Wood, Homer Bailey, Matt Maloney and Sam LeCure to fill two spots. The Braves have similar competition, with Mike Minor, Brandon Beachy and Rodrigo Lopez battling for one spot and Kenshin Kawakami and a slew of top prospects providing insurance.

Detroit’s depth doesn’t compare, but it’s not an oversight on the Tigers’ part. They could have re-signed Jeremy Bonderman. Or they could have held on to Armando Galarraga instead of sending him to Arizona in January. Dombrowski knew other pitchers were available this winter and simply wasn’t overwhelmed by the options remaining once Penny signed.

“We had plan Bs and Cs and Ds,” Dombrowski said in January. “We always have different plans, but a lot of different people didn’t provide the upgrade that Penny did.”

The Tigers are comfortable with Penny’s health and confident in Coke’s ability to transition to the rotation, so they weren’t going to keep Galarraga around as a contingency starter, or sign someone for the sake of signing someone.

All rotations are susceptible to injuries and poor performance, and the 2011 Tigers are no exception. They will undoubtedly have alternatives if they need them, since pitching will be available this summer, as it always is. The difference in Detroit: Dombrowski moved what little MLB pitching depth he had out of the organization while rival GMs added starters in anticipation of the 162-game schedule.