Byron Buxton is feeling better, Rocco Baldelli said Tuesday. The effects of the impact he absorbed by diving for a line drive on Saturday have begun to fade.

But "we're not going to mess around in any way. This is serious stuff," the Twins manager said in announcing that Buxton won't play at all this week while doctors examine the outfielder to make sure no concussion symptoms linger. "It's something that is already resolving itself in some ways, but … we need to take the time and see how he's doing."

Baldelli didn't specify the symptoms Buxton has exhibited, but "he's certainly improving from what he was doing Sunday." But its still being an issue, three days after he dived to catch an Oscar Mercado sinking liner in Cleveland, persuaded the Twins to put him on the seven-day concussion list, which will sideline him until at least Sunday.

"We're going to have him seen by professionals, by the doctors who are going to come in and evaluate him again today," Baldelli said. 'We're going to have a pretty good idea over the next couple of days where he's at."

Ironically, or perhaps appropriately, the decision on Buxton came on the same day he was named the Twins' winner of the Heart and Hustle Award, given to one player on each team by the MLB Players Alumni Association.

Rosario, Cron return

Eddie Rosario's sprained ankle wasn't as harmless as it first appeared either, but the timing of his return came in handy. Rosario, who sprained his left ankle while slipping on first base June 26, was activated from the injured list in Buxton's place, and he returned to the lineup on Tuesday.

"It's time to play again," Rosario said. "The last couple of days in Cleveland, I feel better. I said I feel ready to play. [I'll be the] same Eddie Rosario — I don't want to play too much different."

C.J. Cron was also activated from the injured list, the inflammation in his right thumb mostly — but not completely — gone. "We're halfway through the baseball season. Nobody's 100 percent," Cron said.

Morin DFA'd

In order to activate both Cron and Rosario, the Twins had to cut somebody from the roster, and Baldelli described it as "an extremely tough decision. … There is no right person."

The Twins finally settled upon Mike Morin, a little-noted minor league pickup last December who was enjoying one of the strongest two-month stretches of his career. Morin, whose ERA was 1.66 until his final appearance, was designated for assignment, giving the Twins a week to trade, waive or release the 28-year-old righthander.

"I have no doubt he's going to land on his feet, and he's going to be pitching in the big leagues," Baldelli said. "He's done a great job for this group."

The Twins, however, decided to go with a seven-man bullpen for the moment, and chose to lose Morin — even if he clears waivers, he can choose to become a free agent — rather than option a younger pitcher such as Tyler Duffey or Zack Littell to the minors.

The move, though, opens a third vacancy on the Twins' 40-man roster and one in the bullpen, too, just 15 days before the trade deadline. The Twins are expected to be active in searching for relief help.

Allen used as opener

Former Indians closer Cody Allen served as an opener for Class AAA Rochester on Tuesday and allowed a run on two doubles in his only inning of work against Norfolk. Allen has allowed two runs on four hits in three innings since joining the Red Wings.