Noted orthopedic surgeon Dr. James Andrews will look at images from Bush's latest MRI exam, and coach Sean Payton said Saturday the team expects to have the results by early next week.
Bush was hurt when he was pushed out of bounds in the first half of Thursday night's 27-24 loss in Chicago.
He remained on the sideline, often wearing his helmet and standing up as if eager to keep playing, but Payton held him out after seeing him rush for no gain on the Saints' opening drive of the third quarter.
"I didn't want to play him because I could tell it was affecting him," Payton said. "Once I knew he had sprained it, I didn't want to risk ... injuring it more and putting a player in that wasn't as effective."
Payton also said he has advised offensive coordinator Doug Marrone to leave for his new job as Syracuse's new head coach immediately.
"We felt it was better that he move on to that position and be able to get his staff going, be able to get recruiting going," Payton said.
Although Marrone helped design offensive game plans and coached the offensive line, Payton has been calling the plays and choosing offensive personnel during games, something Bush alluded to when asked why he was held out in Chicago.
"I just work here. I'm just an employee," Bush said after the game. "I don't call the shots. I definitely don't call the plays."
Bush was not present when the locker room at the Saints' suburban training center was opened to reporters on Saturday, but Payton stuck by his decision to focus his play-calling on undrafted second-year running back Pierre Thomas, who accounted for 146 yards and two touchdowns on plays from scrimmage while also returning three kickoffs for 63 yards.
"We all just work here, right? So I don't pay much attention to those comments that we're able to capture after a tough game," Payton said.
Bush has "got to have this thing looked at and evaluated and he's got to stay healthy," Payton said. "Those are the things he's got to do and we'll help him do that in any way, shape or form, but those are decisions I've got to make during the course of a game.
"In his absence, I think Pierre did a pretty good job. We probably moved the ball as effective as we had all night."
Bush had eight touchdowns, including three on punt returns, before tearing the meniscus in his left knee on Oct. 19. He then missed four games before returning to action late last month. Bush had a career-long 43-yard run and scored his ninth touchdown in a victory over Atlanta on Dec. 7, but could be seen favoring his left leg during the Chicago game, after which the team said he had a sprained left knee.
"Obviously, I'm rooting for all those guys. I want to play 'em. I want them to be successful and it's in my best interest that they have success," Payton said. "I just felt like [keeping Bush off the field] was the best decision and I think as we examine where he is right now, I was correct."
Payton has given the Saints off until next Wednesday, when they will begin preparations for the following Sunday's game at Detroit.
At 7-7, the Saints were technically still alive for a playoff berth after their loss in Chicago, but the odds were heavily against them snatching the final NFC wild-card spot. For that to happen, the Saints would have to win their final two games while several teams in front of them would have to lose most or all of their games.
Marrone, among the first assistants Payton hired after taking the Saints' head coaching job in 2006, was prepared to stay in New Orleans for the rest of this season. Instead, Payton congratulated his assistant and gave him the team's blessing to focus exclusively on his new job at Syracuse.
"All of us are happy for him. It's well-deserved. He's done a great job here. ... I've leaned on him heavily. We'll miss him," Payton said. "It's always a good thing when people are interested in your staff. It means you're hiring the right people."
Payton said running backs coach Aaron Kromer would take over coaching the offensive line, while offensive assistant Joe Lombardi will handle the running backs.
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