"When you're not going great, and you're not playing the way you want to offensively, you try to mix and match and get a little spark," Hendry said.
Baker, a 28-year-old right-handed hitter, has played primarily second base, first base and third base in his five-year Major League career, but also has seen time in left and right field.
Ryan Freel, who hit .143 in 14 games for the Cubs since being acquired from Baltimore in May, was designated for assignment to make room for Baker.
The newest Cub, who arrived in the team's clubhouse about an hour and a half before Thursday's first pitch, said he is most comfortable at second and third but added, "Whatever they ask me to do I'll be ready to do, and I'll be prepared."
Baker is a career .257 hitter with a solid .458 slugging percentage, but has spent much of this season on the disabled list after spraining his left hand during a late April at-bat. He spent the past couple of weeks rehabbing the injury with two Colorado Minor League affiliates. In 23 at-bats at Colorado Springs, he hit .217 with one home run and two doubles.
"It was a little rusty there," Baker said of his swing. "Timing was obviously an issue. ... It had been almost two months off. But it was getting better each day, and the big thing is it doesn't hurt, so as long as that's OK, I'll be ready to go out there and compete."
Before his injury, Baker was hitting .130 in 23 at-bats, but last season he hit .268 with 12 home runs and 48 RBIs in 299 at-bats.
"He's a versatile guy, can play three infield position and the corner positions in the outfield, and he can swing the bat a little bit," manager Lou Piniella said. "So he will give us some versatility and a good right-handed bat coming off the bench."