Justin Morneau played catch and took swings off a batting tee Friday, but he knew better than to give a new target date for his return from the disabled list.

Timelines only have discouraged him since he suffered a concussion July 7.

"I've set goals as this thing's been going, and I think that's put more stress on me than [anything]," he said. "I originally wanted to be back after the All-Star break, and I was kind of trying to rush things a little bit. And then, trying to be back when it was time to come off the DL [July 23].

"But now I've come to terms that if we've taken this long, we're going to wait until it's better, and we're not going to rush back. 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."

Morneau also has learned that he can't base his progress on how good he feels while doing his light workouts.

"The problems [headaches, wooziness, etc.] really haven't been during activities," he said. "It's been a couple hours after. So we're kind of waiting to see how the rest of the day goes, and if it goes good, we'll do a little bit more tomorrow, kind of keep going from there."

Morneau only recently began watching the Twins play on TV, since watching TV was something that had been causing the symptoms to return.

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

The Twins optioned pitcher Nick Blackburn to Class AAA Rochester to clear space on the roster for newly acquired closer Matt Capps.

Blackburn went 7-7 with a 6.40 ERA in 19 starts before being sent to the bullpen July 21, when the Twins moved Brian Duensing into the rotation. Blackburn made only one relief appearance, giving up three runs in two innings Sunday.

Blackburn will start for Rochester, which should give him more chances to work on his mechanics.

"Right now it's about getting on the mound and pitching," Twins manager Ron Gardenhire said. "He knows that, and that's why we sent him down."

The Twins have considered numerous starting pitchers on the trade market, but it sounds doubtful that they'll make another move before Saturday's 3 p.m., nonwaiver trade deadline. A person familiar with their discussions said something would have to fall to them at the last minute.

Trades still can be made in August, but players first need to be placed on waivers. The Twins acquired Carl Pavano and Jon Rauch last year in August waiver moves.

The Twins placed infielder Nick Punto on the 15-day disabled list because of a strained left hamstring and promoted infielder Trevor Plouffe from Rochester to take his place.

Plouffe, who batted .130 in seven games with the Twins earlier this year, has come through the minors as a shortstop, but he played seven games at third base for Rochester this year and took some grounders at second base during batting practice Thursday.