Miami RB Daniel Thomas could emerge as the starter if RB Reggie Bush remains sidelined with a knee injury. (Getty Images)

If Miami Dolphins RB Reggie Bush misses a substantial amount of time with a knee injury he suffered in a 23-20 overtime loss to the Jets last week, the team has plenty of options.

Bush confirmed on Monday via Twitter that an MRI revealed there was no structural damage in his knee. However, a timetable for his return to the field remains unclear.

Primary backup Daniel Thomas has rushed for 80 yards and one touchdown on 22 carries this year but has two crucial fumbles in losses to New York and the Texans. Thomas also was sidelined against the Raiders with a concussion.

And if he struggles against the Cardinals on Sunday, the team may yet have an emerging star in rookie RB Lamar Miller.

The first-year player out of Miami had 48 yards on nine carries against the Jets in his first real action of the year. He showed an ability to easily shed arm tackles and continually turned runs outside for extra yards. Miller has come a long way from the player who was inactive for the season opener against the Texans.

“I’m fairly impressed with Lamar,” coach Joe Philbin said. “He’s a very smart football player, takes the coaching real well. I think he’s right on target, where we expect him to be at this time.”

However, not having Bush in the lineup will alter the team’s approach to play calling.

“We expect those other guys to step in and to do certain things,” Philbin said. “Obviously, Reggie, the young guys aren’t quite at Reggie’s level yet. So certain things happen when Reggie’s in there that may not happen otherwise.”

Getting sacked: The Dolphins have made 21 hits on opposing quarterbacks this season -- but just three of those were sacks.

Miami is finding ways to routinely generate pressure with its defensive line, but taking opposing passers down for a loss has been a struggle. DT Randy Starks had two sacks against Houston in Week 1 and DEs Olivier Vernon and Jared Odrick each had a half against the Jets.

“We’ve got to create more sacks, no question about it, but the one positive that I’m seeing is that the completion percentage is like 52 percent,” DC Kevin Coyle said. “I think it’s third best in the league in terms of quarterback completion ratio. So that means that something is happening, whether it be the coverage or the pressure, and I think that the pressure that we’re generating is causing guys to throw the ball away, to make some errant throws and things of that nature.”

For more up-to-the-minute news and analysis on the Miami Dolphins from blogger Dave Carey, follow @CBSDolphins