SEATTLE -- Dave Dombrowski and the Detroit Tigers hope they've grabbed the pieces to round out a playoff pitching staff. The Seattle Mariners just keep searching for the right pieces in their rebuilding efforts.

The Mariners shipped right-handed starter Doug Fister and righty reliever David Pauley to the Tigers on Saturday morning for outfielder Casper Wells, infielder Francisco Martinez, left-hander Charlie Furbush and a player to be named later.

Both Fister and Pauley were packing their belongings into boxes in the Mariners clubhouse ahead of Seattle's game against Tampa Bay. Pauley was noticeably emotional about leaving Seattle but also realized the opportunity he was getting to pitch in a pennant race.

The Tigers started Saturday 2½ games ahead of Cleveland and three games up on Chicago in the AL Central.

"The acquisition cost for a starting pitcher is very high right now, as you can see from the trades being made around the majors. There were times where I didn't think we would get a trade made," Dombrowski said. "Seattle was looking for some offensive help, and they liked Casper Wells a great deal, and they also liked Charlie Furbush, so those were names that were in this early on. We've probably talked 25 times in the last week."