OAKLAND, Calif. (AP) - Jason Giambi is returning to his professional baseball roots with the Oakland Athletics.

Giambi and the A's have finalized a one-year contract with an option, bringing the free-agent designated hitter and first baseman back to the place he began his big league career. The sides had reached a preliminary agreement earlier this week but Giambi still needed to complete the obligatory physical Wednesday for the deal to get done.

Giambi, who turns 38 on Thursday, follows a line of aging and injury-prone designated hitters in recent years with the A's - Frank Thomas, Mike Piazza, Mike Sweeney and then Thomas again.

Giambi also could play some first base to give Daric Barton a break
from time to time.

(Copyright 2009 by The Associated Press. All Rights Reserved.)