Coach Billy Donovan said Friday the senior forward has a bone bruise on his right knee. Prather had some swelling in his knee after Wednesday night's 74-58 win against South Carolina and team doctors initially thought he might have torn cartilage, but tests Thursday revealed no structural damage.
Prather is averaging 17.0 points and leads the SEC in shooting at 62.4 percent.
Point guard Scottie Wilbekin, who left Wednesday's game with a sprained right ankle, is expected to play against the Razorbacks (11-3, 0-1). Wilbekin sat out practice Thursday and Friday, and Donovan said he's unlikely to start.
Center Patric Young also missed practice Thursday with sore knees and guard Michael Frazier II was limited in practice with a calf injury. Young and Frazier should be fine against Arkansas.
Donovan said the injuries are just part of ''the hand that we're dealt. ... We'll go in there as best we can and do the best job we can with what we've got. We'll see who's available.''
The Gators (12-2, 1-0) have won six in a row and 11 of 12, their only loss a buzzer-beater at then-No. 12 Connecticut on Dec. 2.
They have dealt with injuries and adversity for most of the season.
Wilbekin (five games) and Dorian Finney-Smith (two games) were suspended at the start of the season. Freshman guard Kasey Hill missed four games with a high ankle sprain. Guards Eli Carter (leg) and Dillon Graham (hip) are out for the season. Forward Will Yeguete is still recovering from offseason knee surgery, and guard DeVon Walker has missed time with a sprained foot.
Making Donovan's team even thinner, forwards Damontre Harris and Chris Walker haven't played all season. Harris was suspended indefinitely and then left the team with the intention to transfer for the second time in three years. He has since returned to school and is now trying to work his way back on the team. Walker also is enrolled, but is waiting to gain eligibility from the NCAA.
Florida has been so decimated by injuries and suspensions that walk-on Jacob Kurtz, a former team manager, has logged significant minutes.
Without Prather, Finney-Smith will start against the Razorbacks, who have won 23 in a row at home. If Wilbekin doesn't start, Hill likely will take his place in the lineup.
''We're going to need guys to step up for our team,'' Young said. ''Casey is definitely a huge part of our team, but it's not just one guy who's going to be the determining factor if we win or lose. It's going to be a team and collective effort, and if we take care of what Coach Donovan tells us to do, I believe we'll be able to come out with a victory.''
The Razorbacks beat the Gators 80-69 at Bud Walton Arena last season, and they'll need every bit of the home edge if they are to shake the after-effects of a 69-53 loss at Texas A&M on Wednesday. The defeat snapped a seven-game winning streak and once again raised questions about whether this team is ready to snap the program's five-year NCAA tournament drought.
''It humbles you,'' coach Mike Anderson said. ''You think you're playing well, you think you're a pretty good basketball team. We won so many games in a row. Now all the sudden you get smacked in the face.''
The Razorbacks, led by the emergence of sophomore high-flyer Michael Qualls and freshman standout Bobby Portis, were leading the SEC in scoring with an average of 87.2 points and had improved their 3-point shooting from 30.0 percent last season to 37.1 before facing the Aggies.
However, they shot just 4 of 19 (21.1 percent) from behind the arc - as well as 7 of 14 on free throws - and offered little resistance in the second half.
The Razorbacks won't have to look long to find a reason to regain their confidence after having an undefeated conference run at home last season.
''It's like an extra edge,'' junior forward Alandise Harris said. ''People already have a little bit on their mind because they're already scared of the pressure. They know that it's very hard to win here.''
If Arkansas is to challenge the Gators, it likely must have improvement from its two leading scorers, Qualls and Portis.
The two combined to finish 4 of 22 from the field Wednesday, including a 1-of-12 effort from Qualls.
Anderson fully expects both to bounce back - just as he expects the rest of the Razorbacks to perform better in their home arena.
''To me, this will be the true test of our team, what kind of team we're going to be,'' Anderson said.