The Dolphins are just five games into the season, yet one thing has remained constant throughout: Miami is really tough to run against.

Miami goes into Sunday’s game against the visiting St. Louis Rams with the top-ranked run defense in the NFL.

Through those five games, Miami is allowing an average of 61.4 yards, a touch better than the 65.8 yards Chicago is averaging.

Miami’s outstanding run defense started in the loss at Houston in Week 1 as the Dolphins gave up 83 rushing yards to Arian Foster (two touchdowns) and the Texans. The following week, Oakland got just 23 yards on the ground.

The 88 yards picked up by the Jets in Week 3 are the most Miami has allowed this season. The Dolphins’ record for lowest rushing yards allowed came in 1994 when Miami gave up 1,430 (89.4 per game).

“They are great,” Dolphins left tackle Jake Long said. “We have to face them every day so we know how hard they are to run on. We’re all getting better so they are going to just keep getting better.”

Bess grateful

Although he doesn’t do it as much as he used to, the Dolphins still ask the speedy Davone Bess to return punts. So far this season, Bess has returned three punts (with four fair catches) for 30 yards.

At this rate, it’s going to take Bess some time to become the Dolphins’ all-time leader in punt return yards. He’s currently third in franchise history with 1,196 yards — 36 behind Wes Welker (2004-06) for second and 134 behind Jake Scott (1970-75) for the top slot.

“I’m just thankful for the opportunity the Dolphins gave me when I came here in ’08,” Bess said. “I was able to contribute right away, and I’ve just been working on my craft, trying to get better every year after that. I credit my teammates for that. They blocked for me. This certainly isn’t an individual thing. My name may end up being on it, but it’s a team record.”

Bess, one of quarterback Ryan Tannehill’s top options at receiver, is 49 yards away from moving up to 13th on Miami’s all-time list for receiving yards and is within a good game Sunday of passing Irving Fryar to move into the top 10. Bess has caught 22 passes for 346 yards this season.

Injury report

As expected, running back Daniel Thomas (concussion) and cornerback Richard Marshall (back) will not play Sunday against the Rams. Miami’s official injury report also listed Reggie Bush (knee), Nolan Carroll (Achilles), Brian Hartline (quad), Kevin Burnett (ankle) and Reshad Jones (back) as probable. St. Louis quarterback Sam Branford (knee) is probable.

Funny Philbin

Coach Joe Philbin has offered up a few quips over the past few days during his sessions with the media.

On Thursday, when asked what he thought of the offensive line not being hit with a holding call since the opener at Houston, Philbin said the Dolphins “don’t teach to hold. That’s a credit to the guys. They’re good players. Good officiating as well.”

On Friday, he was asked whether one reason the Green Bay Packers (2-3) are struggling is because he left to take the Dolphins job. “That’s a good one,” Philbin said. “I’m sure they’re delighted I’m right where I’m at in South Florida.”