"It's disappointing because the young man had a good last few days and has a bright future in this league," coach Ron Rivera said following Thursday night's practice. "Whatever it entails, he'll get it right and we'll have him ready to go when he's ready."
Gettis injured his knee Wednesday night and was carted off the field after practice. He injured the knee while attempting to run a route.
"It was down in the red zone and he was releasing and he got jammed," Rivera said. "His foot got caught and slipped in a bad direction. It's disappointing. Like I said, the young man was having a really good camp."
Earlier in the night, the Panthers placed defensive tackle Ron Edwards on injured reserve and replaced him with free agent defensive tackle DelJuan Robinson, who played 27 games with three starts in three seasons with the Houston Texans.
Edwards, who received a three-year, $8.5 million contract, tore his triceps in his first practice with the team Aug. 4. It was expected at the time the Panthers would place him on injured reserve.
Gettis had battled back to get on the field after missing portions of training camp with a hamstring injury.
With Gettis out of the lineup, the Panthers are expected to turn to Brandon LaFell, a third-round pick in 2010, to compete with Legedu Naanee, a free agent pickup from San Diego who is familiar with the team's offense.
A sixth-round pick from Baylor in 2010, Gettis started 15 games last season as a rookie and caught 37 passes and had three touchdowns.