"The first diagnosis is not encouraging," said Falcons coach Mike Smith.
Smith would not confirm much about his star receiver's foot injury, but Jones is set for a second opinion in Charlotte Wednesday.
The injury is apparently to the same foot Jones fractured in 2011, but the team wouldn't say what, exactly, has caused the Falcons to fear they've lost Jones for the rest of the season.
And that's news the already struggling Falcons, who have started the season 1 and 4, aren't eager to hear.
Jones is one of the most effective receivers in the NFL, making more catches for at least 40 yards over the past three years than all but two other players. He leads the league with 41 receptions and is second in receiving yards (580) and yards after the catch (248).
It wasn't clear exactly at which point he aggravated his foot Monday, but he did get hit hard before making a spectacular, one-handed catch for 46 yards.
"He's going to be a hard guy to replace, if we have to replace him," Smith said.
The obvious answer, Roddy White, left Monday's game with a hamstring injury, on top of an ankle sprain, and his Smith wouldn't elaborate on when he would return. Harry Douglas doesn't have the speed and height to truly make up for Jones, while Drew Davis has been dealing with an ankle injury of his own.
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