The school released a statement on Tuesday afternoon saying Sidney was suspended indefinitely, but sent another release less than an hour later changing the punishment to a one-game suspension. Mississippi State spokesman Gregg Ellis said the problem was a miscommunication, and that coach Rick Stansbury had not changed his decision.
"Sid is suspended for conduct detrimental to the team," Stansbury said in the second statement. "That's all I'm saying. That's all that needs to be said."
Mississippi State is currently in Hawaii for the Diamond Head Classic tournament and plays Washington State on Wednesday. Sidney will remain with the team.
Sidney sat out his entire freshman season while the NCAA and Mississippi State investigated his amateur status after the Los Angeles Times reported he allegedly received extra benefits during his two-year high school stay in Los Angeles.
Sidney, originally from Jackson, Miss., moved to Los Angeles for his final two seasons of high school.
The NCAA eventually ruled last March that Sidney had to repay $11,800 in improper benefits and sit out the remainder of the 2010 season and nine games this season before he could play.
The NCAA decided he received preferential treatment and improper benefits, and that he also violated ethics rules by providing false or misleading statements.
Sidney returned for the Bulldogs' loss to Virginia Tech at the Atlantis Hotel and Casino on Paradise Island in Nassau, Bahamas on Saturday. Sidney played 25 minutes, scoring 12 points and grabbing three rebounds before fouling out.
The 6-10, 270-pound center was expected to be one of the top big men in the SEC, and Stansbury reorganized his pre-conference schedule to take into consideration Sidney's eligibility.
Stansbury scheduled four games in four days earlier this month, then added an exhibition on the fifth night against Bellhaven (Miss.) in Jackson to give Sidney one game under his belt before Virginia Tech. Stansbury also did this to ensure that suspended point guard Dee Bost would serve all of his 14-game suspension before the SEC opener on Jan. 8.
Bost was academically ineligible for the first semester and drew a nine-game suspension from the NCAA for failing to withdraw from the NBA draft in time to maintain his amateur status in May.
The Bulldogs (7-3) already have lost two home games to lower-level teams in East Tennessee State and Florida Atlantic, increasing the pressure to play well in Hawaii.
Andy Katz is a senior college basketball writer for ESPN.com. Information from The Associated Press contributed to this report.