"I'm excited to be here, to jump into a division race is always exciting," Thatcher said. "I've got a lot of respect for this organization. I'm glad to be here, I've been with Kevin Towers before -- he brought me into San Diego. I'm just grateful for the opportunity to be here and help out any way possible."
Manager Kirk Gibson said that, as in San Diego, Thatcher will be used mostly as a situational lefty who will be expected to get "big outs in high-leverage situations."
"He's got more angle than anybody we've had so far, he's tougher on lefties, has more deception," Gibson said. "We'll use him against righties as well -- he can get righties out. If we use him right, he's got a pretty resilient arm."
During his seven-year career, Thatcher has held lefties to a .209 batting average, striking out more than one in three lefties he has faced (136 strikeouts in 387 plate appearances). This season, lefties are hitting .215 and righties are hitting .280 against Thatcher.
"I know my job here is to get lefties out," Thatcher said, "but I've always taken pride in getting right-handers out, too."
Dave Sessions is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.