ST. PETERSBURG -- B.J. Upton left Wednesday night's game against the Mariners prior to the sixth inning as a precaution, after he experienced tightness in his right quadriceps.

On Thursday morning, Upton sounded like he would be fine.

"Last night it just wouldn't loosen up for me," Upton said. "I went back out for the top of the fifth, the trainers did a little work on me between innings and I felt OK. But once I got back on the turf it kind of tightened up, you know."

Upton did not start on Thursday in the finale against the Mariners.

"Today, I feel good enough to come off the bench," Upton said. "Joe didn't want to start me today. But I feel good enough to come off the bench.

"I plan on being in the lineup [on Friday]. It's not that big of a deal. Precautionary measure, and that's about it."

Peralta gets well-earned day off

ST. PETERSBURG -- After notching a five-out save on Wednesday night, Joel Peralta arrived to Tropicana Field dressed for a day of leisure.

Manager Joe Maddon told Peralta he had the day off after the veteran reliever preserved the Rays' 5-4 win in heroic fashion, earning his first save of the season. So the veteran reliever showed up at the clubhouse wearing beach attire, including swim trunks, straw hat, and flip flops, while carrying a beach ball.

Maddon "said go to the beach," Peralta teased.

Kidding aside, facing Peralta has not been a day at the beach for opposing hitters lately. He has not been charged with an earned run in his last 10 appearances (9 2/3 innings) and has surrendered just three hits during that stretch.

Peralta struggled earlier in the season, when he gave up four earned runs at Boston on April 13 without retiring a batter. After that appearance, Peralta worked with pitching coach Jim Hickey and felt better. Then his long-time pitching coach, Fausto Mejia, flew in from the Dominican Republic to help his pupil, who was struggling with his mechanics at the time.

"[Mejia] is the one who taught me everything from Day 1," Peralta said. "He saw some things. A friend of mine was recording me on video and he watched the videos and called me on the phone and said I was doing a lot of things I wasn't supposed to do. So he bought a plane ticket and came over on [April 20]. We started working out the very next morning and everything started getting better and better."

Peralta noticed a dramatic difference in how his delivery felt after working with Mejia.

"He saw things that probably only he could notice, because he was the one who built me, you know," Peralta said. "And I've been that same guy for 13 years. He saw it and fixed it right away."

Peralta noted that Mejia was the man who converted him from an infielder to a pitcher.

Ailing Zimmer making progress

ST. PETERSBURG -- Baseball icon and Rays senior advisor Don Zimmer has not been with the team since the first weekend of the season due to several hospital visits for different maladies over the past month.

Kidney problems have caused Zimmer's most recent health problem. He is scheduled to begin dialysis immediately.

Rays manager Joe Maddon said he talked to Zimmer on Wednesday.

"Talked to him yesterday and he sounded better," Maddon said. "He wanted to know how everybody was doing. He was Zim being Zim."

Warm-ups becoming hard-hat zone

ST. PETERSBURG -- First Jeremy Hellickson got hit in the head by a batting practice home run in Detroit. Now it seems Matt Moore had his own troubles during pre-game warm-ups.

On Thursday morning, the right side of Moore's face was visibly swollen after getting hit while playing catch with David Price prior to Wednesday night's game.

"I think it deflected off the side of my glove," Moore said. "Pretty wicked, man."

Moore treated his injury with ice and the rookie left-hander said he was fine.