Jones had the knee checked out before arriving at Turner Field. The MRI showed a buildup of fluid and bone rubbing against bone, which is what's causing all the pain.
There's no structural damage, however, and Jones didn't even consider coming out of the lineup.
"We'll worry about next year next year," he said. "The fact of the matter is the pain's not going away."
Jones asked trainer Jeff Porter how long it would take to get over the pain and was told, "It will start feeling better around Thanksgiving."
The struggling Braves had a one-game lead in the NL wild card with two games left in the regular season. Despite a September slide that has wiped out nearly all of their once-comfortable advantage, they could clinch a second straight trip to the playoffs with a win over the Phillies and a loss by the St. Louis Cardinals, who were playing Tuesday night at Houston.
Jones has been one of the Braves' top hitters over the past month, hitting .307 (37 of 118) with eight homers and 15 RBIs in his past 33 games. He staked Atlanta to an early lead in Monday night's game with his 18th homer and later reached on a ground-rule double. But he hit into an inning-ending double play in the eighth with the potential tying runs on base.
The Braves took their third straight loss, 4-2, but remained in the wild-card lead when the Cardinals lost to Houston 5-4 in 10 innings.
Manager Fredi Gonzalez said he might have to pinch-run for Jones late in the game or put in a defensive replacement if Atlanta has the lead. The third baseman especially has trouble pushing off on grounders to his left.
But at least going against Philadelphia Roy Oswalt should ease some of the pain. The switch-hitting Jones will hit left against the right-hander, which takes some of the pressure off his knee.
"It's bruised, but he's in there," Gonzalez said. "He wants in. He doesn't want to come out of that lineup and I didn't expect him to. We'll adjust as the game goes on."
The manager was asked if Jones would be playing with a similar injury in June.
"No," Gonzalez quickly replied. "But this isn't June. This is September."