GLENDALE, Ariz. - Arizona Cardinals cornerback Antonio Cromartie said he won't know the severity of his hyperextended left knee until Monday.

The nine-year veteran went down near the Cardinals sideline in the third quarter and left the game after walking off under his own power. He did not return.

Antonio Cromartie walked off the field unassisted after hyperextending his left knee in the third quarter of Sunday's win. AP Photo/Rick Scuteri

Cromartie said he didn't know how he hyperextended his knee.

"Everything's OK," Cromartie said in front of his locker after the Cardinals' 23-14 win over the San Francisco 49ers. "I will find out what's going on with it tomorrow. I really can't do anything standing here."

Cardinals coach Bruce Arians reiterated the uncertainty surrounding the injury.

"We don't know if it's reinjured, what the extent of it is," Arians said.

Cromartie tore his left ACL and LCL in 2005 heading into his senior season at Florida State Seminoles and hyperextended his right knee in October of last season with the New York Jets.

Cromartie later tweeted he's fine and will be ready for Arizona's next game, which comes after its bye week, at the Denver Broncos in Week 5.