ZANDVOORT, Netherlands (Reuters) ¿ Twice US Masters winner Bernhard Langer aims to become the oldest European tour winner when he takes part in the Dutch Open this week.

German Langer, who lines up with his 17-year-old amateur son Stefan this week at Kennemer, is 49 and eligible for the seniors' tours when he turns 50 on Monday.

After recovering from kidney stones, which forced him to withdraw from the Players Championship in Hamburg last month, Langer said he was raring to go if not yet fully fit.

"I was out of action for about two-and-a-half weeks and I am not as fit as I was four weeks ago," Langer told a news conference. "You deteriorate pretty fast lying around for over two weeks but I have been working hard and I'm gaining strength and endurance."

Langer has turned down an opportunity to take part in the lucrative Fedex Cup on the US PGA Tour this week to play in a full tour event for the first time with son Stefan.