How good will the Tigers’ starting rotation be in 2015?

The Detroit Tigers saw a significant drop in production from their starting pitching rotation in 2014, by comparison with their historically good 2013 rotation. After trading Doug Fister for three players who contributed nothing in 2014, the team’s rotation ERA climbed from 3.44 to 3.89, their WHIP rose from 1.21 to 1.27, and their fielding independent pitching (FIP) went from 3.12 to 3.88.

The Tigers’ rotation still easily led the league in WAR, innings pitched and wins, and their FIP still ranked second to the Indians. The number of strikeouts declined almost a full strikeout per nine innings from an all time major league record in 2013. The Tigers’ defense behind their pitchers cost the club about half a run per nine innings, by comparison with a league average defense.

The club’s 2015 rotation doesn’t figure to be much improved due to the offseason personnel moves, which include the departure of Max Scherzer and a trade of Rick Porcello to Boston. Former Cy Young winner David Price will be with the team for a full season, and he figures to replace Scherzer as the ace of the staff. A comparison between the two pitchers over the past three seasons paints an optimistic picture, with both pitchers ranked among the top four in the American League over that period of time.

Scherzer and Price, 2012–2014

In place of Porcello and Drew Smyly — who went to Tampa Bay in the trade for Price — will be five-year veteran Alfredo Simon, and Shane Greene, who had an impressive rookie season with the New York Yankees in 2014.

Greene worked just 78 innings for the Yankees in his rookie campaign, posting an ERA of 3.79, a FIP of 3.64, and a WHIP of 1.37. The Tigers would be very happy if he can maintain that level of performance for roughly the next 150 innings in 2015.

Simon, who was converted from bullpen work to the Cincinnati Reds’ rotation in 2014, was an All-Star in the first-half of the season, with a 2.70 ERA, a FIP of 4.33 and a WHIP of 1.05. Simon struggled after the break, however, posting an ERA of 4.52, a FIP of 4.34 and a WHIP of 1.44. The fact that his FIP remained constant and his ERA was more in sync with that in the second-half doesn’t make for a rosy forecast.

This chart shows that Simon is capable of replacing some of Porcello’s numbers, although doing so in such an inconsistent fashion won’t yield the kind of value that Porcello provided on a consistent basis in 2014.

Smyly's numbers above are for the full 2014 season, and he pitched better after leaving Detroit. If we were to limit his numbers to just his starts with the Tigers, we should also include Price's second-half efforts, and the comparison becomes even less favorable for the 2015 rotation.

The best shot that the Tigers have of boosting the performance of their rotation is for Anibal Sanchez to remain healthy for the full season, and Justin Verlander to at least partially recapture the form that he displayed prior to his off season core muscle surgery prior to the 2014 season. The next chart displays the drop in production from the starting pitchers who figure to be the second and third starters in the Tigers’ rotation in 2015.

* Sanchez joined the Tigers at the trade deadline in 2012

With all the stars in the Tigers' rotation recently, it's easy to forget that Sanchez led the American League in ERA in 2013, and that he has consistently posted some of the best numbers in baseball. He had a higher WAR in 125 innings in 2014 than either Verlander or Porcello racked up in over 200 innings each.

The additions of Jose Iglesias at shortstop, Anthony Gose in center field, and Yoenis Cespedes in place of Torii Hunter in the outfield, should give the Tigers’ run prevention efforts a boost as well. It is worth noting that the Tigers’ rotation ranked fourth in the league with a 58 percent fly ball to ground ball ratio in 2014, while their HR/FB ratio of just 7.5 percent was the best in the league. That is an area where both Simon and Greene need to improve, but the spacious grounds of Comerica park could help in that cause.

An optimistic view of the Tigers' starting pitching heading into the 2015 season would have Price replacing all the lost production of Scherzer, Verlander recovering at least part of what he lost in 2014, and Sanchez remaining healthy for a full season while pitching at the same level. That would make up for the deficit that Simon and Greene are unlikely to fill by themselves. An improved defense could then cut the number of runs allowed to put the team in a position to win enough games to take their fifth straight division title.