Fox said Monday that Delhomme fractured a finger on his throwing hand late in the fourth quarter of Sunday's loss to the New York Jets and may be replaced by untested Matt Moore next week against Tampa Bay.
Delhomme is scheduled to visit a specialist Tuesday.
The injury could sideline Delhomme late in the worst season of his career. He threw four more interceptions against the Jets, completing only 14 of 34 passes for 130 yards with a passer rating of 12.7. The Panthers (4-7) didn't score a touchdown in the 17-6 loss that virtually eliminated them from playoff contention.
Delhomme has a career-high 18 interceptions this season, tied with Detroit rookie Matthew Stafford for second-most in the NFL behind Chicago's Jay Cutler (20). Fox considered benching Delhomme a month ago after he threw three picks in a loss to Buffalo, but decided against it.
Fox was again supportive of his beleaguered QB on Monday, despite another game where he struggled with his accuracy.
"If his finger wasn't an issue, I couldn't with a straight face make a change just with him," Fox said. "That was a combined effort by the offensive players, not just one player. ... It was poor not just by the quarterback."
Fox said Delhomme was hurt when his hand was hit while throwing a 24-yard pass to Dwayne Jarrett on fourth-and-14 with 2:25 left. Fox wouldn't say which finger on his right hand was broken and said they didn't know the severity of the injury until Delhomme was examined Monday morning.
Delhomme, who threw nine passes and an interception after the injury, didn't appear in the locker room during the media availability period Monday.
Fox said Delhomme would be "hard-pressed" to take snaps at practice on Wednesday. That could leave Moore as Carolina's starter for the first time since late in the 2007 season when Delhomme was recovering from reconstructive elbow surgery.
"We'll see how things shake out later in the week," Moore said. "I've been here before."
He'd be taking over an offense in disarray, weighed down by Delhomme's woes, key injuries to the offensive line, and various other miscues.
Delhomme had an interception returned for a touchdown Sunday when Steve Smith ran the wrong route. Delhomme's pass bounced off his heel into the hands of Darrelle Revis, who raced 67 yards. Delhomme was under pressure for most of the day and was sacked three times, and the Panthers managed only 75 yards rushing.
"Obviously we didn't do a good enough job preparing them," Fox said of the offense. "We weren't ready to play and that starts with coaching, all the way down to the players' responsibility."
The 6-foot-3 Moore, who went undrafted out of Oregon State, played in nine games as a rookie with three starts, throwing three touchdowns and five interceptions. Moore didn't appear in a game last season and has played in only one game this year, throwing a single incomplete pass against Arizona after Delhomme was shaken up.
Moore has stayed ahead of journeyman A.J. Feeley on the depth chat. Feeley was signed early in the season when Josh McCown was placed on injured reserve. But there have been questions about whether Moore has a firm grasp of the offense.
"We haven't had a chance to see a whole lot of him in live play lately," Fox said. "I think he's capable of making all the throws, has the height, weight and arm strength you look for.
"The quarterback position is about decision-making, and until you get in there in live situations, you really never know. And he hasn't had that opportunity a lot."
The injury could provide a needed break for Delhomme, who hasn't been the same since throwing five interceptions and losing a fumble in last season's playoff loss to Arizona.
The Panthers gave the 34-year-old Delhomme a lucrative contract extension in the offseason, but he's looked far from the QB that led the Panthers to a Super Bowl appearance in 2003 and a berth in the NFC championship game in 2005. Both years he had 16 interceptions, his previous career high.
Delhomme's 59.4 passer rating this season ranks 31st in the NFL and his 55.5 completion percentage is below his 59.7 career mark entering this season.
Fox said RB DeAngelo Williams played through a sprained ankle in the second half Sunday. ... WR Dwayne Jarrett (ankle) and DT Tank Tyler (knee) were also banged up. ... FB Brad Hoover said he "tweaked" his ankle in his first game back from injury, but "I don't see it keeping me out" against the Buccaneers Sunday.
Information from The Associated Press and ESPN NFL Insider Adam Schefter was used in this report.