The 5-foot-9, 209-pound Slaton was released by Houston on Tuesday.
The Dolphins consider Bush their top running back, even though he ranks third on his own team and 51st across the NFL in yards rushing through three games. Bush had 13 yards on 10 carries in last weekend's loss to Cleveland -- his second-worst total in 29 career games in which he had double-digit rushing attempts -- and lost a fumble at the Browns' 19-yard line late in the first quarter.
So on Wednesday, after a practice where the music blaring inside the Dolphins' practice bubble was akin to something that would accompany a prizefighter entering the ring, Bush said there's no better time than now to change things around.
"It's going to come," said Bush, who has 69 yards on 27 carries so far with Miami. "I've just got to be patient and not press too much. This last game, I got caught pressing a little too much. I've been in this league long enough that I shouldn't be having any turnovers. I had a turnover last game that was pretty costly in the red zone. Correct the mistakes, continue to practice, continue to chop away and we'll be fine."
Slaton was a third-round pick in 2008 and was the NFL's top rookie rusher with 1,282 yards. He rushed for 437 yards but fumbled seven times in 2009 and was placed on injured reserve after 11 games. He had neck surgery after the season, and never regained his form.
Arian Foster emerged in 2010, and Slaton was relegated to backup duty and returning kicks. Foster has been limited by a left hamstring strain early this season, and 2010 second-round pick Ben Tate topped 100 yards rushing in Houston's first two games. Slaton has only seven carries for 20 yards this season.
Defensive end Ryan Baker was waived to make room for Slaton, who ran for 1,282 yards for Houston as a rookie in 2008 but only 550 in parts of 26 games since.
Information from The Associated Press contributed to this report.