"He's somebody we've actually talked to them about since Spring Training," said Rays executive vice president of baseball operations Andrew Friedman. "We feel like he's going to help us defensively. And we like his bat against right-handed pitching. We feel like he has a good mixture at the plate between patience and power from the left side. And feel like he'll fit us and help us win games."
Gross can play both right and center fields, but he became expendable with Tony Gwynn Jr. getting healthy and center fielder Mike Cameron being set to return from a 25-game suspension next week, leaving the Brewers flush with outfielders.
"Something had to give," Gross said. "I do my best not to try to figure this game out, as far as trades and different things like that. We've got a lot of quality baseball players and a lot of quality outfielders. When Mike comes back, there's going to be a lot less playing time."
Gross had moved into a starting role for Milwaukee with injuries to Gwynn and Gabe Kapler ( right shoulder) and had just started to produce. After going 2-for-3 against the Cardinals on Monday, he was 2-for-4 in Tuesday's Brewers win and scored three runs including the game-winner on Kapler's single in the bottom of the 12th inning.
Gross walked and stole second base to spark the rally. He's batting .209 with two RBIs for the season, but has come on over the last week.
"I really struggled the first couple of weeks," said Gross, who entered an April 16 game in St. Louis batting .091. "I was hitting the ball hard and not getting any hits. Really, in the last four or five days, I've really, really started feeling good. Hopefully, that can continue and I can go down there and help [the Rays] win ballgames."
Friedman said the Rays were trying to get as much balance on their roster as they can.
"But, obviously, there's more right-handed pitchers in this league then there are left-handed pitchers," Friedman said. "We feel like he can help us on both sides of the ball."
Friedman was non-committal when asked if Gross would platoon with Jonny Gomes in right field.
"We'll let [manager] Joe [Maddon] sort all of that out," Friedman said. "But he's a guy we think can help our offense and also help us defensively. We like him, and we feel like in the context of our roster ... with our personnel, we feel like he can help us win games."
Justin Ruggiano appears to be the most likely candidate to be sent down to make room for Gross on the 25-man Major League roster. Friedman would not speculate about what move would be made.
"I don't know yet," Friedman said. "We'll talk about it tonight. This just came together. After the game, I'll talk to Joe about it some. I'm not even sure when he's going to report yet, tomorrow or the next day, so we won't make a move until we know he's going to get here."
The Rays do not have to clear a spot on the 40-man roster for Gross, due to catcher Mike DiFelice's being designated for assignment on Tuesday.
Butler was 0-2 with a 6.35 ERA in three starts at Class A Vero Beach this season. Last season he posted a 3.34 ERA between Class A Columbus and Vero Beach. He was selected in the second round of the 2006 First-Year Player Draft out of the University of San Diego.
Bill Chastain is a reporter for MLB.com. Adam McCalvy contributed to this report. This story was not subject to the approval of Major League Baseball or its clubs.