Saints running back Deuce McAllister missed practice today because of a swollen left knee, and coach Sean Payton says he’ll get an MRI to determine whether there’s cause for concern.

Payton said it swelled up after yesterday’s practice and trainers had to drain fluid from it.

McAllister started the first three games of the season last year before suffering a torn ACL in the left knee. He had surgery to repair the ligament, and he also had off-season surgery on his right knee, which he blew out in 2005.

Jeff Duncan of the New Orleans Times-Picayune writes, “the normally easy-going McAllister didn’t have the look of someone who was unconcerned.”

If healthy, McAllister would likely be the Saints’ starting running back, splitting carries with Reggie Bush, with Aaron Stecker and Pierre Thomas also likely to see playing time.