BOSTON -- Now that Red Sox third baseman Mike Lowell is back to full baseball activities, the plan is that he will be activated on Tuesday night, when the Red Sox open their next homestand against the Toronto Blue Jays.

For the second day in a row, Lowell took batting practice on Wednesday and felt no discomfort from the left thumb he sprained on April 9. He also fielded ground balls.

Lowell will go on a three-game rehab assignment for Triple-A Pawtucket beginning on Friday, when he will serve as the designated hitter. Lowell will be at third base Saturday and he'll DH again on Sunday.

Pawtucket is home on Friday, and in Buffalo on Saturday and Sunday.

The Red Sox are off on Monday, but some members of the coaching staff will come to the park so Lowell can have a workout in preparation for his return on Tuesday.

With Lowell out of the mix, Kevin Youkilis has been playing third base with reserve Sean Casey getting the nod at first.

But the Red Sox will be gladly welcome Lowell -- the World Series MVP last October -- back into the lineup.