Jon Kitna done for season?

ARLINGTON, Texas -- The Dallas Cowboys are concerned that their fullback and backup quarterback won't be able to play again this season.

Owner/general manager Jerry Jones acknowledged after Thursday's 20-19 win over the Dolphins that he was uncertain whether Jon Kitna (back) and Tony Fiammetta (undetermined illness) would be able to recover from their ailments before the end of the season.

"We just don't know, and that is all we know, that we don't," Jones said. "Both of those guys are not definitive in any way medically."

The Cowboys' medical staff has still not been able to determine the origin of the illness that has sidelined Fiammetta the last two games, Jones said. Coach Jason Garrett described the primary symptom this week as nausea when Fiammetta exercised.

Jones spoke about Fiammetta again Friday on his twice-weekly KRLD-FM radio show.

"It shouldn't be cloaked in mystique," Jones said. "It's hard for him to do some things without nausea or without being incapable of doing them. So he's certainly under the care of a real evaluation. Right now we can't and he can't function the way you have to, to play football. We don't know, that's it."

The running game has suffered without Fiammetta, a ferocious lead blocker. The Cowboys average 145.8 rushing yards per game and 5.6 per carry when Fiammetta plays. Those averages fall to 85.6 yards per game and 3.2 yards per carry when Fiammetta is inactive.

Kitna has also been inactive the last two games because of a sore back that has not responded to treatment. Jones said Kitna's condition was one of the primary reasons the Cowboys tried to claim quarterback Kyle Orton off of waivers this week.

Tim MacMahon covers the Cowboys for ESPNDallas.com.