MINNEAPOLIS -- Justin Morneau was activated from the disabled list on Friday, two days after Twins manager Ron Gardenhire surprisingly said he would be rejoining the team in time for a series opener against the Indians.

The Twins formally made the transaction on Friday morning, activating the four-time All-Star and placing outfielder Jason Repko on the 15-day disabled list with left shoulder bursitis, a move that is retroactive to Thursday.

Morneau, who underwent surgery to remove a herniated disk fragment in his neck on June 29, hadn't been expected to rejoin the team until Monday at the earliest.

But the slugger looked impressive in his first six games with Triple-A Rochester, hitting .423 with a home run, four doubles and eight RBIs after going 2-for-4 with a homer and three RBIs on Wednesday. He went 0-for-6 in his seventh game on Thursday.

"He's killing the ball," Gardenhire said Wednesday. "He's swinging really good, and feels great. He basically said, "Get me out of here, please. It's really hot in Durham.'"

Morneau was originally placed on the disabled list, retroactive to June 10, with a sprained left wrist, before electing to undergo neck surgery later in the month. He was hitting .225 with a .619 OPS, along with four homers and 21 RBIs in 55 games before hitting the DL.

He was bothered by problems with his neck and left wrist all season before his trip to the disabled list.

It's been a tough year and a half for the first baseman, as he missed the second half of last year with a concussion suffered on July 7 in Toronto. He was putting up MVP-type numbers before the season-ending injury, as he was hitting .345 with a 1.055 OPS and 18 homers in 81 games.

Gardenhire said he's hopeful that now that Morneau is fully healthy again, he can get back to his old ways.

"If we get the guy back who is driving the ball the other way now, and the guy who we've seen hit and be healthy, then I think it'll be real entertaining to watch him," Gardenhire said. "We've seen how he can carry a ball club. If we can get him back and keep him on the field, it will be really entertaining not only for the rest of this year, but maybe having a guy healthy for the start of next year, and we'll go from there."

Casilla makes quick recovery, will return Friday

MINNEAPOLIS -- Twins second baseman Alexi Casilla made quick progress with his strained right hamstring, and will be activated from the 15-day disabled list on the first day he's eligible on Friday in Cleveland.

The club made the official announcement after Wednesday's 5-2 win over the Red Sox, as infielder Trevor Plouffe was optioned to Triple-A Rochester to make room for Casilla on the 25-man roster.

Casilla has been taking batting and fielding practice, as well as participating in running drills, this week at Target Field, and is ready to make his return, according to Minnesota manager Ron Gardenhire.

"Casilla feels fantastic," Gardenhire said. "He'll be activated for Friday night's game in Cleveland. His legs feel good, he's running, the whole package."

Casilla was hitting .259/.322/.369 (average/on-base/slugging) with 15 stolen bases and 21 doubles in 96 games this season before injuring his hamstring while running the bases against the Rangers in Texas on July 27.

He bounced back after a rough start, as he hit just .167 in April, but hit .281 with a .751 OPS over the next three months before his injury.

"I think we saw him starting off scuffling a little bit, but as the season has gone along, he's been one of our better players," Gardenhire said. "We all know about the athleticism and the plays this guy can make. But we're seeing that consistency we saw a few years ago, and that's all it's ever been about with Alexi."

Plouffe, meanwhile, is expected to work on his defense while with Rochester, as he made his fourth error of the season on Wednesday, while playing shortstop. He's already proved he can hit in Triple-A with 15 homers and a 1.019 OPS this year, but is hitting just .202 with five homers with the Twins.

"We want him to play everywhere," Gardenhire said. "We've already been working with him at shortstop on his arm angle and throwing the ball over the top. So he's going to play shortstop, second and in the outfield. ... More than anything else he has to continue to work on his defense."

Revere back in right for first time since June

MINNEAPOLIS -- Twins rookie Ben Revere made his fifth start in right field Wednesday, and his first since June 6.

Denard Span in center field and Delmon Young in left made up the rest of the outfield, marking the fourth time Twins manager Ron Gardenhire has filled out the lineup card that way this season.

Traditionally, the outfielder with the strongest arm is in right field and the weakest is in left, but the Twins' did just the opposite with Revere and Young.

"We're not going to move Delmon, he's fine out there," Gardenhire said. "Paul Revere out there, he likes to ride, so he'll be fine."

Since coming to the Twins in 2008, Young has not played an outfield position other than left field, despite having played 163 games in right field and 30 in center field during his two years at the Major League level with Tampa Bay.

Revere has played 11 games in left, seven games in right and 58 in center. Span also has 124 career games in right field and 74 in left field, but Gardenhire does not want to move him out of center field, either.

"You can't start [messing] with Delmon, moving him around out there," Gardenhire said. "He's played it, too, but he hasn't been there in a long time. Revere will do fine. It's a big outfield out there ... we'll see what happens."