Both Stoudemire (sprained ankle) and Shumpert (sprained MCL) had been listed as game-time decisions.
"(The ankle) feels great," Stoudemire said. "I got some treatment this morning. Hopefully everything feels good.
"I'm ready to get started to get back out there and get us back on track."
Stoudemire started and Shumpert came off the bench.
Neither will play with any specific limit on minutes against the Bobcats, said coach Mike D'Antoni.
"When they start sucking wind, which they will, I'll try to get them rest," D'Antoni said. "But Amare said he's raring to go."
Stoudemire suffered a sprained left ankle last Thursday against the Los Angeles Lakers. He has missed the Knicks' last two games, including their 90-85 home loss to Toronto on Monday. Shumpert suffered a right MCL sprain in the Knicks' season-opening win over Boston. He rolled into Chris Wilcox in the third quarter of the game and immediately left the floor.
Shumpert wore a knee brace Wednesday night.
"It just keeps me from hyper-extending it," he said. "I feel better with it. It will restrict some of the movement. It doesn't limit me athletically, though."
With the Knicks at 2-3 and coming off an ugly loss to the Raptors, they sorely need the offensive shot in the arm Shumpert and Stoudemire can provide.
The offense has leaned heavily on Carmelo Anthony in Stoudemire's absence. Anthony, who called Shumpert a "game-changer," scored 35 points and grabbed 11 rebounds against the Raptors. Outside of a 12-point third quarter by Toney Douglas, the Knicks didn't have another scoring threat. Rookie Josh Harrellson struggled on Monday in place of Stoudemire, scoring just two points in 33 minutes.
Harrellson returned to a reserve role with Stoudemire (17.3 ppg) back in the lineup.
The Knicks originally thought Shumpert would be sidelined for 2-4 weeks. He missed just nine days by returning against Charlotte.
"I was kind of leaning on my youth to get me back quick," the 21-year-old guard joked on Tuesday.
Shumpert scored 11 points and grabbed four rebounds against Boston. He impressed players and coaches with his aggressive approach during training camp. D'Antoni said on Tuesday that Shumpert will likely be reinserted in the second unit and share the backcourt with fellow reserve Mike Bibby.
Ian Begley is a regular contributor to ESPNNewYork.com. Information from ESPNNewYork.com contributor Jared Zwerling was used in this report.