Kellogg, a former McClymonds High standout, was the leading scorer during West Coast Conference play last season at 17.2 points per game.
"I feel that it is in my best interests to move into a pro career and support my family," Kellogg, who has a young baby daughter, said in a statement. "I really enjoyed my time at the University of San Francisco, but right now I feel that this is the proper path for me."
Kellogg played in 28 games as a sophomore for the Dons last season, starting 25 for 13-18 USF. He also led the WCC in steals (2.4 per game) and was the Dons' top assist man (3.6 per game).
Dons coach Jessie Evans said that he understands Kellogg's decision.
"We are supportive of what Antonio wants to do," Evans said. "The young man gave us all that he had on the court, but he feels that it is time to move on and take an important step in his life."
Kellogg's name appears nowhere on mock NBA drafts online, and would seem to have little chance of catching on with an NBA team. Evans said it's most likely Kellogg will try to sign with a team in Europe or play in the NBA's developmental league.
Kellogg, who had formed an all-Oakland backcourt with Armondo Surratt of Oakland Tech, missed a pair of games due to academics this past season.
However, Debbie Gore, USF's executive director of athletics, pointed out that Kellogg is NCAA eligible.
Kellogg joined USF after being dismissed from the University of Connecticut squad in 2005 for violating team rules. His best game for the Dons was a 37-point effort in an overtime victory over San Diego.