"There's no fracture," Greene said after the Jets' crushing 17-13 loss to the Denver Broncos.
The Jets, already without backup LaDainian Tomlinson (sprained knee), were forced to use their third- and fourth-string backs for three quarters.
Joe McKnight rushed for 59 yards on 16 carries, and caught a team-high six passes for 62 yards.
Rookie Bilal Powell, in his first NFL action, ran for 11 yards on seven carries.
Powell contributed to the Jets' only touchdown, but not in a positive way. He fumbled at the Denver goal line, but guard Matt Slauson pounced on the loose ball.
It was the first touchdown by a Jets offensive lineman since guard Randy Rasmussen in 1972.
Greene was hurt as he went down on a four-yard screen pass, grimacing in pain as he hit the turf. He walked off under his own power and was taken to the locker room for further examination. He returned to the sideline.
"I was ready to go back in the game," he said.
This isn't Greene's first rib injury. He suffered a significant injury in the 2009 AFC Championship Game. The good news for him is, the Jets have 10 days before their next game.
Tomlinson sprained his left knee Sunday night against the New England Patriots and didn't make the trip.
Rich Cimini covers the Jets for ESPNNewYork.com.