Bush has missed five games since fracturing his right fibula in Week 2. Earlier this week, Bush said doctors gave him permission to test his leg at full-speed in practice.
But when the Saints took the practice field on Wednesday, Bush was off behind one end zone, working out on a step-climbing machine and a stationary bike.
It was a sign of progress for a player who for the past few weeks has usually been in the training room while his teammates were on the field.
Saints coach Sean Payton said Bush did some running on his own the past two days.
"We just keep taking it day to day and monitoring the progress, monitoring the next day after the workout and kind of go from there," Payton said.
The Saints (4-3) say they don't like to use injuries as an excuse for sagging performance, but there's no question that a number of key players have missed action while New Orleans has lost three of its last five games.
Injuries have also afflicted running back Pierre Thomas, starting linebacker Scott Shanle, starting cornerbacks Tracy Porter and Jabari Greer, starting strong safety Roman Harper, starting defensive end Will Smith and others.
"The disappointing part is you haven't seen the complete team since Week 2 when Reggie went down," said Shanle. "It absolutely has an effect. I mean, we do a good job of having guys who are backups come in and play good football, but there's a reason why Reggie Bush is Reggie Bush and Pierre Thomas has done what he's done."
In the same game that Bush went down, nickel back Randall Gay was concussed and, following a brief comeback, has since been placed on injured reserve.
Thomas, who was last year's leading rusher and a productive outlet for Drew Brees on screen passes, sprained his ankle in Week 3. Harper missed a Week 4 contest against Carolina with a hamstring pull. Porter, who went down in Week 4, needed arthroscopic surgery to repair the lateral meniscus in his left knee and has not played since. Smith strained his groin in Week 4 and missed the next game. Shanle pulled a hamstring in practice in Week 6 and has missed the past two games. Greer left the Week 6 game at Tampa Bay with a left shoulder injury and has yet to return.
Now there are signs that the Saints are on the mend.
All-Pro safety Darren Sharper, who opened the season on the physically-unable-to-perform list while recovering from offseason knee surgery, finally came back last weekend to a defensive backfield that played without its top three cornerbacks.
Thomas, who has been absent during recent practices, was on the field in a jersey, participating in the team stretch and doing some light jogging.
Shanle returned to practice on a limited basis. While Porter and Greer were not officially listed on the injury report as having practiced, both were at practice doing some light individual work.
"The progress with both Jabari and Tracy has been significant and positive and on schedule," Payton said.
Bush, Thomas and Porter were not available to speak with reporters after practice. Greer said he was "optimistic" about returning this Sunday, as was Shanle.
Brees said the Saints believe their best football is still to come, adding that the rash of early season injuries could pay off in the long run.
"We faced this last year, but just later on in the season," Brees said, referring to the Super Bowl champs' three-game skid just before the playoffs. "Obviously we're facing it much earlier now.
"Are we more injured than other teams? Probably most of them," Brees continued. "It's allowed an opportunity for some young guys to step up and play pretty well. I think that will serve us well down the road, once we get everybody back."
The Associated Press contributed to this report.