Portis told 106.7 The Fan on Tuesday that he's awaiting the results of an MRI on his left groin, which he injured during Sunday's 17-12 victory over the Philadelphia Eagles.
"I don't think the team would even let me attempt to go and try to play on Sunday," Portis said. "But who knows? ... I'm going to take my time and make sure I'm healed."
Portis said Sunday that he felt a "pop" in his groin before leaving the game.
"It's bothering me," he said Tuesday. "It's stiff."
Portis has just 195 yards on 49 carries this season. His playing time already was on the wane with the emergence of Ryan Torain, who was promoted from the practice squad two weeks ago.
Portis missed the last eight games of last season after suffering a severe concussion in a helmet-to-helmet hit.
Copyright 2010 by The Associated Press