MINNEAPOLIS -- Shortstop Trevor Plouffe was recalled to the Twins 25-man roster after infielder Nick Punto was placed on the 15-day disabled list prior to Friday's series opener against the Mariners.

Punto, who left Wednesday's game against the Royals in the eighth inning when he lunged for first base, had an MRI on his left hamstring which revealed enough damage to warrant a stint on the DL, retroactive to July 29. Plouffe returned to the Twins for the third time this season.

In 90 games with the Red Wings, Plouffe has batted .259 with 20 doubles, four triples, 15 home runs and 48 RBIs. Plouffe appeared in seven games for the Twins this season, spanning from May 21 -- his Major League debut -- through June 17. He has hit .130 with three RBIs.

Manager Ron Gardenhire said that the Twins called Plouffe, who was sick at home with the flu, on Thursday, informing him of the news. Gardenhire joked that the call-up was "a good remedy to get better real quick."

Plouffe was doing drills at second base before Friday's game, but Gardenhire said it was most likely that Plouffe would be found at shortstop during this big league stint.

"He has work to do at second; he's played very little of it," Gardenhire said. "He'll get plenty of work over there at second, but right now he's going to play shortstop."

Morneau takes swings prior to Friday's game

MINNEAPOLIS -- Twins first baseman Justin Morneau has seen the day he was eligible to leave the 15-day disabled list come and go, but for the first time in his recovery from a concussion, that doesn't worry him.

Morneau, who has been sidelined since accidentally taking a knee to his head on July 7 in Toronto, has been doing light workouts at Target Field and continues to see progress in his recovery.

"It's frustrating, but it's been a lot more positive this week seeing progress," Morneau said. "It's been obviously longer than we'd like, but to see progress is good."

Before Friday's game against the Mariners, Morneau went through his usual routine of warming up, stretching and playing catch, before he took some swings in the batting cages for the first time.

Both Morneau and manager Ron Gardenhire said the roughly 25 swings the first baseman took in the cage went well, but Morneau added that his headaches and dizziness don't normally come on until several hours after an activity is completed.

The team doctors were coming in at about 6 p.m. CT to examine Morneau, but as of game time things were positive for him.

If things continue to look good for Morneau, he and the club's trainers will gradually add more and more activity to his routine as he continues to recover. The one thing Morneau said he needs to avoid is setting a deadline for himself because that just adds to his stress and frustration of not being in the lineup.

"I think I've set goals as this thing has been going, and that's put more stress on me than doing it," he said. "I originally wanted to be back after the All-Star break so I was trying to rush things to get back, and then rushing when it was time to come off the DL, so I've been doing that the whole time and now I've just come to terms with it."

Morneau added the most frustrating part of his recovery was sitting at home and watching his team lose ballgames and not being able to help in any way. However, he said the Twins' recent success on the road trip was exciting for him because it was nice to see the club progressing on the field -- much like he's been progressing by not being there.

Although the progress has been slower than anticipated, Morneau said he has no problem continuing the slow pace to get back into the lineup.

"We've taken this long and we're going to wait until it gets better and not rush it," Morneau said. "When it's better, it's better, and we'll be happy and we'll be out there for the rest of the season playing."

Blackburn optioned to Triple-A

MINNEAPOLIS -- With the Twins acquiring right-hander Matt Capps through a trade with the Nationals, the organization needed to do something about its 14-man pitching staff.

Prior to Friday's game against the Mariners, the Twins decided the best option was to send right-hander Nick Blackburn to Triple-A Rochester to make room for Capps and allow the former starter to throw more innings.

Blackburn was removed from the starting rotation on July 21 and was sent to the bullpen, where he made only one appearance, pitching two innings against Baltimore. He gave up three runs and five hits.

Twins manager Ron Gardenhire said that although the right-hander has been having throwing sessions with pitching coach Rick Anderson, Blackburn is not throwing enough innings to regain his role in the starting rotation.

"He needs to pitch. Talking with him, I think he recognized that too," Gardenhire said. "Right now, it's about getting on the mound and pitching, and he agreed with that, too."

Blackburn went to Rochester with a 6.66 ERA through 104 1/3 innings, with 77 earned runs.

It was undetermined how long the right-hander would remain in Triple-A.