The Blue Jays gave Dustin a three deal for $4.1 million, and it doesn't make very much sense to me. Besides starting 4 games last season, he hadn't pitched in a major league game since the 2008 season.
Before his injury Dustin McGowan looked like he could have a decent major league career. In 2007 he struck out 20% of the batters he faced, but struggled with walks, walking over 8% of the batters he faced. He also did a good job at limiting home runs, only giving up .74 per nine innings. In all he had a 3.73 FIP, to go along with a 3.79 xFIP, and a 2.4 rWAR, a solid back end of the rotation guy at minimum. In 2008 he saw his strikeouts decrease by 3%, but also saw a decrease in walks. His home runs per nine virtually had no change. His FIP didn't change much either, it was 3.81, but he saw his xFIP spike to 4.27. After his 2008 season he only managed .7 rWAR.
McGowan's biggest issue is staying healthy though. Since 2008 he's gone through a pair of shoulder surgeries, and a knee surgeries. As you should know shoulder injuries are some of the toughest to come back from (See Johan Santana), and at any moment he could injure that shoulder again, and be done for the year.
Dustin McGowan is guaranteed a spot in the rotation for now, but the second he becomes ineffective or gets injured the Blue Jays may be wondering why they gave him the three year extension in the first place.