The first pass thrown in Bush's direction bounced off his shoulder pads and helmet. He later dropped a likely touchdown and then fumbled on a punt return to set up a short touchdown for the Dallas Cowboys, though the Saints rallied to win 30-27 on Thursday.
"I don't like to think of myself as rusty at all, but maybe it is," Bush said. "That was just a mental error on my part. ... Those are things that we can't have and that they can get you beat. Next week, we'll get better."
Bush had been listed as questionable after practicing on a limited basis during a short week of light team workouts before the Saints' first Thanksgiving Day game. He got hurt Sept. 20, the second week of the season, while recovering his muffed punt at San Francisco.
Though Bush started, the versatile running back was limited. He carried only once for a yard and caught only one of the three passes thrown his way for 12 yards.
"There's certainly frustration," coach Sean Payton said. "The first game back for a player such as him is always difficult. He's healthy and there are some things that he'll obviously have to continue to work on. I think it's challenging to him to not have the normal work week. ... I don't know that benefited a guy coming back off an injury as long as he's been injured. That being said, he's very competitive."
With the Saints up 20-13 soon after halftime, they had third-and-7 from the Cowboys 10 when Drew Brees threw a pass to Bush wide open over the middle. Catch the ball, and he likely walks into the end zone. Instead, they had to kick a field goal.
"I kind of reached out and I've got to make those catches," Bush said. "Nine times out of 10, I'm going to make those catches."
The bigger mistake came a few minutes later when Bush fielded a punt and took off running. But he fumbled when he was hit from behind by Jesse Holley.
"We knew they wanted to get the ball in his hands. He likes to bounce to the outside. When he went the other way, I had to run him down," Holley said. "We knew he carried the ball loose. That's what he does. So I wanted to first get the tackle, then come in with the strip."
Six plays later, the Cowboys scored to get to 23-20.
"With the turnover, you just can't have those type of mistakes in a crucial situation like that in the game, when the game is on the line," Bush said. "That's a mental error on my part. I've got to clean it up and I've got to play better. But it did feel good to get back out there and get my feet wet. ... The important thing was we got a win."
The broken leg capped a difficult few weeks for Bush, who gave back his Heisman Trophy. The NCAA punished Southern California after concluding that Bush and his family improperly accepted money and gifts from sports agents while Bush played for the Trojans. Bush said he returned the award to end the controversy.