Liriano, Perkins and Duensing are battling for the No. 5 spot in the rotation

The Twins began spring training Thursday with the luxury of having their starting lineup set as far as position players (with the possible exception of third base) and the bullpen in place. Among the starting pitchers, there is some intriguing competition to keep an eye during the next month. Scott Baker, Carl Pavano, Nick Blackburn, Kevin Slowey appear to the established as 1-4 in the rotation, though not necessarily in that order. The fifth spot in the rotation remains a bit of a mystery. The Twins did not have a bona fide fifth starter at all last season, and after Slowey’s season-ending injury in early July, they struggled even to find a reliable fourth starter until they acquired Pavano in early August. The Twins have three viable candidates for the fifth spot in the rotation – lefthanders Brian Duensing, Glen Perkins and Francisco Liriano.

Duensing, unknown to most Twins fans before last season, was a pleasant surprise. Duensing made his MLB debut out of the bullpen last season on April 10 against the White Sox. The Twins promptly sent Duensing back to Rochester when Scott Baker came off the disabled list. Duensing was back on the team as a reliever on July 2. Less than one month later, however, Duensing found himself making an emergency start when Liriano had to miss a start due to an elbow injury. He went back to the bullpen after that, and the Twins didn’t make him a consistent starter until late August. In September, he contributed mightily to the Twins’ surge by winning three straight starts against Oakland, Detroit and the White Sox. And he won Game 162, which enabled the Twins to face Detroit in the tiebreaker. Duensing will not scare a lot of hitters, but he is considered a crafty pitcher who does not give into hitters. And unlike Perkins and Liriano, he did have a solid 2009 campaign and transitioned nicely from reliever to starter.

After a promising 2008 season during which he went 12-4 in 26 starts, Perkins had a rocky 2009. He pitched effectively at times but had problems maintaining any sort of consistency. He struggled with his control often last season and was responsible for some big innings from opponents. At Yankee stadium in May, he gave up 6 runs and could not escape the first inning. Two months later in Oakland, he surrendered 8 runs in the first inning. Perkins’ season was cut short due to a shoulder injury, with his last appearance coming on August 8. Perkins finished with a 6-7 record in 17 starts and 5.89 ERA. Perkins is fierce competitor with a lot of swagger and emotion on the mound. Of course, this works well for him when he’s on his game but can make him more easily frustrated when he’s not hitting his spots. On the plus side, he has above-average stuff with a nasty changeup and curveball.

Liriano appeared to be destined for greatness before an elbow injury sidelined him toward the end of his dazzling rookie season in 2006, when he went 12-3 with a 2.16 ERA and made the AL All-Star team. Liriano underwent Tommy John surgery and missed the entire 2007 season. Liriano made just 14 starts in 2008, but posted decent numbers (6-4, 3.91). Last season was a disaster. Liriano won just a handful of games in 29 starts and posted a dismal 5.80 ERA. Control problems have contributed significantly to his decline. During many of his appearances in 2009, Liriano seemed to completely lose command of his pitches. He walked 65 batters in 136 2/3 innings, nearly one batter per two innings pitched. It is true that Liriano has lost some zip on his fastball and that his slider is not as devastating as it was in 2006, but he still has good enough stuff to make him a strikeout pitcher when he can locate his pitches effectively. This is evident by the fact that he averaged eight strikeouts per nine innings last year. And despite his struggles last season, optimism is high for Liriano heading into this season after he led the Leones de Escogido to a Dominican Winter League title this offseason while posting a 3-1 record with a miniscule 0.49 ERA in seven starts.

So who’s the frontrunner among this trio of lefthanders? It’s a tough question to answer, but I would have to give the edge to Liriano simply because I believe he still has the most potential of the three. It may be unrealistic to think that he can regain his dominant 2006 form, but he’s certainly capable of being an effective starting pitcher as long as he can locate his pitches. And while his success in the Dominican league are far from a guarantee that he’ll pitch better this season, it certainly has raised his confidence level. The fact that he slimmed down this winter also should help his stamina.

Like Liriano, Perkins has also had a big season and faltered afterward. The difference is that Perkins has never been as dominant as Liriano was in 2006. But he was pretty good in 2008, and if he can get back to that level he would be a very starter at the back of the rotation. If Perkins can stay healthy and maintain his control and composure, he will definitely be in the mix for a spot in the rotation.

I view Duensing as the underdog, which may not be fair considering he pitched much better than Liriano and Perkins last season. Liriano and Perkins have an edge over Duensing because they are more experienced and have nastier stuff. The good news for Duensing is that he has quite a bit of experience as a reliever and has a good chance of locking down a spot in the bullpen if he doesn’t make the cut as a starter.

The Twins managed to win the Central Division last season despite the fact that they did not have a deep or consistent starting rotation. It would be very difficult to do it again, especially given the fact that the White Sox and Tigers possess formidable starting pitching. The Twins fortunes will be helped tremendously if either Perkins or Liriano (and hopefully both) can regain their old form, or if Duensing can fill in adequately if they don’t.