Blackburn was 4-9 with a 7.39 ERA in 19 starts this season, with a team-high 23 home runs allowed. When he opened the season 0-4 with a 6.84 ERA, it was supposedly because he was too strong and his sinker ball wasn't sinking—a bad thing for a sinker ball pitcher.
With his demotion the Twins recalled Liam Hendriks to take his spot in the starting rotation. The move now makes Hendriks the only pitcher left from the opening day roster that included Jason Marquis (released and now pitching for the Padres), Francisco Liriano (traded to the White Sox) and Carl Pavano (shutdown for the season by the team).
In order for the Twins to send Blackburn to Rochester he had to clear waivers—which he did. That means every other major league team knew what the Twins finally learned—Blackburn was not a major league pitcher.
Before calling him up in 2007, Blackburn had compiled a 40-40 record over six minor league seasons. Once he arrived in Minnesota it didn't get any better.
Over six major league seasons his best season record was 11-11, something he achieved in 2008 and 2009. His career mark is a pedestrian 43-55 with a 4.85 ERA.
Yet for some reason he was repeatedly given a chance to pitch for the Twins. Perhaps because without a true ace on the staff, his break-even record was just good enough to get another turn.
For now, Hendriks joins the 4-D pitching rotation, led by Scott Diamond, Sam Deduno, Cole De Vries and Brian Duensing. These four are a combined 18-16 in 48 starts with a 3.92 ERA. Even though Diamond has the biggest influence on the rotation's numbers at 10-5 with a 2.95 ERA, the 4-Ds are better than the 11-28 record and 6.40 ERA in 50 starts for Pavano, Liriano, Marquis and Blackburn.
Now the Twins can start the process of putting together the team's 2013 starting rotation.
After his breakout season, Diamond is a lock to make the rotation next season.
Deduno, pitching for his third major league team in three years, needs to finish the season strong if he wants to return. Over parts of eight minor league seasons he is 45-45 with a 4.18 ERA. This is the first chance he has gotten to start in the majors. He has been just wild enough to be effective. In 46 innings pitched, Deduno has issued 36 walks with only 30 strikeouts, throwing only 57.9 percent of his pitches for strikes. Yet he has a 4-1 record in eight starts.
De Vries, who signed with Minnesota as an amateur free agent in 2006 is a long shot to return. Currently with a 2-4 record and a 5.04 ERA in eight starts, he most looks like a Blackburn replacement.
If Duensing can regain the effectiveness he had in 2010 when he finished with a 10-3 record and a 2.92 ERA with 13 starts in 53 games, he would be an effective starter. The problem is he is only 11-19 in 37 starts since then with a 5.34 ERA.
The wild card in the new rotation is Hendriks.
In his eight starts for the Twins he is 0-5 with a 7.04 ERA, while at Triple-A Rochester he is 9-3 with 2.20 ERA.
There's a good chance that three of these five end up in the starting rotation next season. Which two join Diamond will be determined over the next seven weeks.
Hopefully, one of them won't be Blackburn, again.