DETROIT -- Justin Morneau's headache still had not gone away by Friday afternoon and the first baseman is now questionable for not only the rest of the Twins' series against the Tigers this weekend, but also for next week's All-Star Game due to his lingering concussion symptoms.

Morneau was out of the Twins lineup for a second straight day due to the mild concussion he suffered on Wednesday night. The injury occurred when he was accidentally kneed in the head by Blue Jays second baseman John McDonald while sliding into second base to break up a double play in the eighth inning of a 6-5 loss at Toronto.

Twins manager Ron Gardenhire said that the first baseman was "not available" for Friday's series opener against the Tigers. Morneau, who has been considered day-to-day, was expected to undergo another examination before the game by the team's training staff to see if he's doing any better.

Morneau was unavailable before Friday's game, but he said through a team spokesman that there was no change in his status since Thursday.

Following Thursday's series finale in Toronto, Morneau said that he would not rush himself back on the field having dealt with head injuries before in his career -- including a concussion he suffered back in April of 2005 that forced him to go on the disabled list.

"You can play through a sore knee or a banged up wrist, but the head is not really something you want to mess with," Morneau said on Thursday. "Having had a concussion before and knowing the long term effects, we want to make sure we're good for the rest of the year instead of something that lingers for months."

Gardenhire said the team has not yet discussed whether Morneau, who was voted in by the fans to start at first base, will take part in next week's All-Star Game. He said the club would likely wait to see if Morneau is able to play on Saturday or Sunday before the team doctors and general manager Bill Smith would consult with Morneau about the right thing to do.

"I would imagine if he's missed [the whole Detroit series], it wouldn't make much sense to go to the All-Star Game," Gardenhire said.

In place of Morneau, designated hitter Jim Thome was slotted to bat cleanup for the Twins on Friday night against the Tigers.

"He's one of the things we went after this winter for when you have to have a Morny out of there or a [Joe] Mauer out of there, you stick another big lefty in there and just kind of roll with it," Gardenhire said. "It's a lot nicer when we have Morny in there and Mauer in there. But this is a good thing to be able to plug Thome in the four hole and go from there."