Aaron Cook

Cook battled back from injuries to make 17 starts for the Rockies last season, but the results were brutal. He's never been one to miss bats, instead relying heavily on his high groundball rate and the defense behind him to get hitters out. That skill was still present last season (55.1 percent groundball rate), but Cook's walk rate was elevated (3.43 BB/9IP) and pitching as heavily to contact as he does offers little margin for error. Cook signed a minor league deal with the Red Sox and was invited to spring training, so he may stick in a relief role given his inability to stay healthy and that he might be an ideal fit for situations where a groundball would create a double-play opportunity.

2010 was a disappointing year for Cook as he had a poor first half of the season (3-5 with a 4.88 ERA and 1.485 WHIP) and missed much of the second half due to injuries (foot, toe, and shin). He was able to maintain his groundball rate (58.1 percent) and avoid the long ball (0.78 HR/9IP), but the control issues that he battled early in his career once again reared their head. His 3.67 BB/9IP walk rate was his highest since 2003, his first full year in the majors. Never one to dominate hitters, unless Cook ceases to issue so many free passes, his upside remains limited.

Part staff ace, part workhorse, Cook remains one of Colorado's most consistent starting pitchers. Despite opening the year with a shoddy April, allowing 20 runs through 25 innings, Cook was able to grab hold of the reins and have a productive first half of the season, posting an ERA just above 3.00 and eating 83 innings between May and the All-Star break. The second half of Cook's 2009 campaign was marred by injury, but he regained full health before the year closed out. None of his numbers will jump out at you from a fantasy perspective, but as one of the more dominant groundball pitchers in the National League, he remains a decent value pick as someone to equalize your ERA and pick up wins despite his hitter-friendly home park.

One of the most extreme groundball pitchers in baseball, Cook was hurt by the loss of Kaz Matsui and the injuries to Troy Tulowitzki, but still managed to make the All-Star team and post the second-lowest ERA of his career. He's an unsexy pick -- a Rockies starter who doesn't strike people out -- whose value fluctuates wildly from league to league since he offers value for deeper leagues or those with more of an emphasis on wins.

Cook owns one of the best sinkers in the game that consistently hits the low 90's. He'll begin 2008 as the Rockies' No. 2 starter behind Jeff Francis. Cook pitches to contact, which means he doesn't strike out many (61 K in 166 innings) and he gives up a lot of hits (178). It's worth noting his 5.31 home ERA was over two runs higher than on the road (3.07). He did miss the last month and a half of 2007 because of a strained ribcage, but Cook is expected to be ready for the start of spring training.

The good news: Cook managed to stay healthy and pitched a career-high 212.2 innings in 2006. The bad news: too many of his sinkerballs found their way into the outfield as base hits. Cook seems tailor made for Coors Field, with his excellent 2.77 G/F, but a lack of a dominant strikeout pitch allowed batters to hit .288 off him in 2006. He has the potential to post an ERA near 4.00 (assuming the humidor stays), but offers little else.

Cook missed the first half of 2005 recovering from blood clots in his lungs. When he returned for the final two months of the season he was stronger and more resilient than ever, winning seven of his last eight decisions. His greatest asset is a sinkerball that has proven to be effective in the thin air of Coors Field. He records most of his outs through groundballs and does not register many strikeouts or walks. Believe it or not, he's Colorado's ace.

Cook finished 2004 on a promising note, going 3-1 with a 2.55 ERA over his final six starts before blood clots forced him out in August. He allowed only seven home runs in 96.7 IP, showing signs of being effective in the thin air of Coors Field. If he's healthy enough to start the season in Colorado's rotation, fantasy owners in deep NL-only leagues can give Cook a look, but it's hard to imagine a Rockies pitcher with significant fantasy value in 2005.

Originally drafted by the Rockies in the second round of the 1997 draft, Cook is widely regarded as one of two future aces of the Rockies, along with Chin-Hui Tsao. He's yet to show the ability to dominate opposing hitters in the majors. Similarly, he never struck out a ton of hitters at any stop, but his ratios are good and his control has never been an issue. The Rockies have said that they want Cook to make the team as a starter. He's got a great repertoire and it appears that all he needs now is a bit of poise, a chance and some time.

Cook rocketed up from Double-A to the majors last year, and he held his own despite not being able to dominate opposing hitters. He's probably pegged to begin the year in the starting rotation, but given that he hadn't quite mastered being able to dominate Triple-A hitters before his call-up, he's a bad bet to succeed initially.