MINNEAPOLIS -- Twins first baseman Justin Morneau is scheduled to see another head and concussion specialist on Tuesday in the Twin Cities, and it's still unclear exactly when he might be able to return to the field.

Morneau has been battling lingering symptoms from a concussion that he suffered on July 7, and Twins manager Ron Gardenhire said on Monday that it's doubtful the All-Star will be cleared to travel with the team to Baltimore later this week.

Morneau initially suffered the concussion when he took an accidental knee to the head during a slide into second base during a game in Toronto. Friday marks the first day that Morneau would be eligible to come off the disabled list, but the expectation is that it will take more time before he's ready to be back.

"You talk to him, he's groggy and he can't do anything about it," Gardenhire said. "How long it's going to last, nobody knows. The doctors can only guess, too, with this stuff. It's all on how the player feels. When the symptoms leave, he can get back to baseball activity. "

Morneau has not been at the ballpark in recent days, because he's been told to stay home and rest. Gardenhire said that Morneau has been waking up in the mornings and feeling better, but some of his symptoms, such as headaches and grogginess, have returned later in the day.

"Concerned? Absolutely," Gardenhire said. "I'm concerned that he gets healthy before we even think about anything else. The big thing right now is with him just getting healthy and them telling us, 'OK, he's ready to go.' And no one is even close to doing that right now it sounds like."