Hayden Panettiere Not Dating Mark Sanchez, Says Source

By Sarah Durham Wilson

06/01/2011 at 12:30 PM EDT

Hayden Panettiere may have just split with with Ukrainian boxer Wladimir Klitschko – but the petite Scream 4 actress was spotted in Malibu over the Memorial Day weekend with New York Jets quarterback Mark Sanchez. On Monday, the two stepped out for a bite at an In-n-Out Burger with friends.

So, are they more than just burger buddies?

"They're not dating at all," a source tells PEOPLE. "They're really just friends."

RELATED: Hayden Panettiere and Wladimir Klitschko End Their Romance

Another source tells PEOPLE that they've been spotted together for months – but maintains they are just friends.

In addition to heavyweight boxer Klitschko, the actress, 21, has also dated her former Heroes costar Milo Ventimiglia as well as Hills alum Stephen Colletti.

• Reporting by JULIE JORDAN and BLAINE ZUCKERMAN