The Cubs have had to rely on the bullpen in the last two games because of short outings by starters Mark Prior and Sean Marshall. With the trade of Williamson, the team might add right-handers Michael Wuertz or David Aardsma from Triple-A Iowa, or it could add both if Marshall has to go on the disabled list as expected.
Williamson, 30, was 2-3 with a 5.08 ERA in 31 games for the Cubs this year, and he is coming off a disappointing outing Saturday against the Nationals. He was pressed into duty in the fifth inning when starter Sean Marshall had to leave the game with a strained left oblique. Williamson gave up three runs on three hits and two walks over one-plus innings in the Cubs' 7-3 loss.
"I've never done it before," Williamson said about pitching without any warmup in the bullpen.
The right-hander has primarily been used as a late-inning setup pitcher in his career, and he was the Cincinnati closer in 2003, when he saved 21 games. In 2004 with Boston, Williamson posted a 1.26 ERA in 28 games.
"It's frustrating," Williamson said after Saturday's game. "I'm a competitor and trying to do the best I possibly can."
He has made a comeback from two Tommy John surgeries on his right elbow and has dealt with minor aches and pains this season. Williamson was on the disabled list in June with tendinitis in his right elbow.
"We'll see what happens," Williamson said after Saturday's game about his name being mentioned in possible deals. "I've been traded before, and it worked out real well."
The Padres have a slim lead in the National League West, and they can use the veteran help in the bullpen. Williamson definitely has benefited from the multiple roles he's handled with the Cubs.
"It's a learning experience," Williamson said. "Stan Belinda always told me ... I'll never stop learning in this game, and by God, he was right. Nothing ceases to amaze me, the stuff you go through. It should make me better."
After Saturday's game, he complimented Cubs general manager Jim Hendry and manager Dusty Baker for the way they've handled him, and he didn't blame anyone.
"It's no one's fault but mine," Williamson said. "I'm the one throwing the baseball."
He's actually been more effective against left-handers this year, holding them to a .172 average compared to .257 by right-handers.
Jimenez, a left-hander, was 5-7 with a 4.43 ERA in 17 games for the Fort Wayne Wizards. He is 14-29 in 72 Minor League appearances, including 60 starts, with a 5.13 ERA. He has struck out 54 in 87 1/3 innings.
Santo, a right-hander, was 6-6 with a 5.38 ERA in 20 games, including 15 starts. He has given up 96 hits and walked 54 over 92 innings while striking out 48. Santo was named the 16th-best prospect in the Padres organization going into this season by Baseball America.