He hasn't played since suffering headaches and fogginess following a jarring dive for a ball hit down the line on Aug. 28, and if he does play again this season, it won't be in the field.
"He's not ready to play baseball," manager Ron Gardenhire said before his team dropped a doubleheader to the White Sox on Monday at Target Field, 2-1 and 4-0. "I won't play him in the field the rest of the season, and we've talked about that."
Playing strictly as the designated hitter, the manager said, would keep Morneau "from diving around and banging himself up."
Morneau missed the last 78 games of the 2010 season because of a concussion, but the flare-up of symptoms last week was a surprise. Though Morneau has been bothered by neck, arm and wrist injuries all season, the concussion had become a bitter memory for the 2006 AL MVP, or at least eclipsed by new injuries.
Morneau had surgery June 24 to repair a ruptured disk in his neck that was causing pain, weakness and numbness up and down his left arm. All told, he has played in only 69 games this season and is batting .227 with four homers and 30 RBI.
That Morneau, 30, re-injured himself after a notably active game -- he also was thrown at out second trying to tag on a fly to center field and dived to complete an unassisted double play -- calls into question his future as a first baseman, and makes the decision to play Joe Mauer at that positoon seem prescient.
Mauer, Gardenhire said, will "see his fair share of action at first base" over the team's final 21 games.
--C Joe Mauer still hasn't recovered from an upper-respiratory and ear infection, and he served as the designated hitter in each of the past three games.
Mauer hasn't caught a game since Aug. 20, one of the reasons the Twins have three catchers on the roster; Drew Butera and Rene Rivera are the others.
"Once he gets past this flu bug, he'll be able to catch," manager Ron Gardenhire said. "I have three catchers. I'll keep Joe on the field any way I can. If it's at first base, then that's what I'll do. I'm sure he would like to catch a few games."
--LHP Francisco Liriano, on the 15-day disabled list since Aug. 26 with a left posterior shoulder strain, was cleared to do some light throwing before Monday's first game and vowed to return this season.
"My shoulder felt fine," he said. "There was no pain at all. To be honest, I expected it to be sore, but it was OK. The way it feels now, I think I can pitch again (this season)."
Liriano will throw again Tuesday and be re-evaluated by trainer Rick McWane.
--CF Denard Span on Monday started a workout program he hopes will get him back on the field before the season ends Sept. 29. Suffering from migraines, Span hasn't played since Aug. 13, and he has missed 81 games since suffering a concussion on June 3.
"There are times I feel good for about 35 minutes when I'm doing things, then I get spaced out," Span said. "I'm trying to battle through the energy level. I want to get some games in. I don't want to go into the offseason without playing at all."
Span returned to play 10 games in early August but went 2-for-35 (.057) and admitted he didn't feel right.
"A lot depends on how my body reacts to the daily activities," he said. "I've been working out at my own pace the last week or so. I know when to back off if I start to get a certain feeling. This is not a normal injury. It's really mentally challenging."
--RHP Liam Hendriks, 22, is scheduled to make his major league debut when he starts Tuesday's game against the White Sox at Target Field. Hendriks started the season at Class AA and went a combined 12-6 with a 3.36 ERA between New Britain and Class AAA Rochester. The Twins still have to open a spot on the 40-man roster for Hendriks.
--RHP Nick Blackburn, done for the season after being placed on the 60-day disabled list due to a right lateral forearm strain, is prepared to give his injury more time to heal.
"At least there's no damage," he said. "It's only inflammation, and that was the original diagnosis. There's no great way to speed up the process, so time will be the ultimate thing to heal it."
Blackburn's last outing was a two-inning start against the Yankees on Aug. 21, a short performance that resulted in a 3-0 loss. He finishes the season 7-10 with a 4.49 ERA.
--INF Matt Tolbert will be recalled from Class AAA Rochester, and 1B Chris Parmelee and OF Joe Benson will be recalled from Class AA New Britain on Tuesday as the Twins continue to expand their roster.
Tolbert, 29, has played 74 games for Minnesota this season, posting a .202 average in 204 at-bats.
Parmelee, 23, hit .287/.366/.436 with 13 homers and 83 RBI in 142 games for New Britain.
Benson, 23, batted .385/.388/.495 with 16 homers and 67 RBI in 111 Class AA games this year.