New York Giants offensive tackle David Diehl has been ruled out for six weeks with a thumb injury.

Diehl had hoped to play through the injury and practised with a cast on his hand yesterday, but an MRI scan convinced the Giants that surgery was the best course of action.

The 32-year-old will undergo the procedure today and is expected to miss six weeks.

"Giants offensive lineman David Diehl will undergo surgery this afternoon to repair his unstable right thumb. The surgery will be performed by Dr Robert Hotchkiss at the Hospital for Special Surgery in Manhattan," read a statement on the team's official website.

"Diehl practised yesterday with a cast on his right hand. After an MRI and examination by Dr. Hotchkiss this morning, it was determined the injury required surgical repair.

"The expected timeframe for recovering from the surgery is approximately six weeks."

The injury is expected to rule Diehl out for the remainder of the Giants' pre-season schedule as well as at least four regular season games.