Josh Willingham will undergo an MRI Tuesday on his ailing left knee. Willingham has been dealing with soreness in the knee for a couple weeks now, and the pain was bad enough Monday that he had to be scratched from the lineup. Even if no structural damage is found, the Twins might decide to play it safe and shut Willingham down through the All-Star break. The outfielder is batting .224/.356/.398 with 10 homers and 37 RBI this season.