It's been a busy week for the Tigers. Yesterday, they traded starting pitcher Doug Fister to the Nationals in a four-player swap which angered much of the Tigers internet community. Today, they have signed free agent closer Joe Nathan to a two-year contract, a deal which is being received better by Detroit fans.
The downside to Nathan is that he recently turned 39 years old and doesn't throw as hard as he once did. According to Brooks Baseball, his average fastball has dropped from 96 to 93 since 2007 and he now throws almost as many sliders as four-seam fastballs. The good news is that his results have not been affected much at all.
Pitching in a hitter's haven in Texas in 2013, he posted a 1.39 ERA (fourth in the American League), struck out 73 batters and allowed just two home runs in 64 2/3 innings. He also finishing second in Win Probability Added (4.18) and fifth in RE24 (17.75), two numbers that take into account the situations in which relievers pitched.
The best thing about Nathan is that he has been consistently dominant since 2003 other than missing 2010 due to Tommy John surgery and struggling to recover in 2011. In fact, only three pitchers - Mariano Rivera, Trevor Hoffman and Goose Gossage have higher lifetime WPAs than Nathan. That is some impressive company.
Despite Nathan's advanced age, I like this signing as he showing little indication of decline and was in my opinion the best free agent closer available. The Tigers were also rumored to be interested in Brian Wilson and Grant Balfour, but Nathan has the more consistent track record.
The Tigers greatest needs are now a set-up man and left fielder. They may go cheap in the bullpen, but they are rumored to have interest in left-handed outfielder Shin-Soo Choo and switching hitting Carlos Beltran. Former Tiger Curtis Granderson is also available. There had been some talk about center fielder Jacoby Ellsbury, but it looks like he's going to the Yankees.