"Hey everyone in Austin, tx ... kill yourself," wide receiver Jaz Reynolds wrote on the microblogging service after a University of Texas at Austin student opened fire with an AK-47 assault rifle at campus library before killing himself.
Reynolds later posted: "everyone in Austin tx disregard that last tweet. Ya'll will mess around and do it. LMAO."
In suspending Reynolds for at least one game, Oklahoma Sooners football Coach Bob Stoops said his school's "rivalry with Texas will not come at the expense of dignity and respect."
"We have great concern for what happened in Austin and I am incredibly disappointed that someone connected with our team would react so callously," Stoops said in a statement. "We have taken immediate action and I hope by doing so we have illustrated how seriously we view this matter."
The messages from Reynolds, who has no catches this season, came days before the No. 8 Sooners and the No. 21 Longhorns meet at the Cotton Bowl in Dallas Saturday for an annual rivalry game.
Tuesday's shooting prompted a campus lockdown but no one else was harmed.
The shooter, 19-year-old sophomore math major Colton Tooley of Austin, said last year, for an assignment on a controversial, contemporary issue, that "he was most interested in researching public perception of gun control in the U.S. over the last 20 years, especially after the Columbine and Virginia Tech shootings," The Daily Texan student newspaper reported Thursday.
In the April 20, 1999, Columbine High School massacre near Denver, two students killed 12 students and a teacher before committing suicide. In the April 16, 2007, Virginia Tech massacre, a senior English major killed 32 people before committing suicide.