Baldelli, 26, was placed on the 60-day disabled list on March 28 with a mitochondrial disorder, a condition that slows muscle recovery and causes fatigue, costing him the first 116 games of the season. He also missed the final 124 games of 2007 because of a hamstring injury.
Baldelli was activated before Sunday's game, when Carl Crawford went on the 15-day disabled list with a finger problem.
"For the first time in my life, I don't really get nervous about things, but before the game I couldn't eat that much," Baldelli said. "I don't know if I was just excited or what, but it was fun and it was a happy day for me, and I think a lot of people, my family and friends and everyone.
"There were times when I didn't know if I was going to be playing anymore. I honestly didn't know. There were some scary times, too. And all of that is behind me, hopefully. And things look good. I came out of it feeling good. I'm just really, really happy now."
Baldelli grounded out to the pitcher in his first at-bat before lining an RBI single into left field his next time up. He struck out and grounded out in his final two at-bats. He also made a diving catch in right field in the fifth inning on a sinking line drive by Bryan LaHair. Gabe Gross replaced Baldelli in the middle of the sixth inning.
Baldelli's teammates were excited for him to be back.
"Anytime somebody can come back after contemplating retirement because of something you can't control, just getting back is awesome, it's a little emotional," pitcher Andy Sonnanstine said.
Catcher Shawn Riggans talked about all of Baldelli's quality attributes as a player, then added, "He's a first-class guy, and I just love having him around."
Rays manager Joe Maddon was pleased observing Baldelli's baseball instincts.
"The guys were clapping a little bit [after Baldelli's hit]," Maddon said. "He got up in the box because he was facing a knuckleball pitcher, which I liked, the awareness was there. The baseball IQ is good.
"And he wasn't jumpy. He was taking borderline pitches, swung at strikes, worked good at-bats for his first time out in a while. ... And of course, the hit, that felt good for him. I just think the fact that he got out there, he's going to sleep really well tonight."
Bill Chastain is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.