"I had to get here," said Keppinger, who was batting .324 in 39 games before he fractured his left kneecap on a foul tip on May 13. "It seems like we've been having a problem at shortstop. Shortstop has been a little bit of a bad position for us this year with a lot of guys going down."
Keppinger, who batted second on Sunday, had been filling in for the injured Alex Gonzalez. Two more shortstops went on the DL since Keppinger went down. Jerry Hairston Jr. suffered a fractured thumb on June 9, and Jolbert Cabrera dislocated his left index finger on Friday.
Rookie Paul Janish was the team's lone remaining shortstop, but he entered Sunday's play in a 2-for-30 skid. The Reds told Keppinger after Friday's game that he would be brought back early from his rehab assignment at Triple-A Louisville.
"I kind of figured," Keppinger said. "The game was on TV there, and I saw Jolbert get hurt."
Originally, the plan was to wait to bring Keppinger back until at least Friday -- after the Blue Jays series -- or next Monday, when the Reds return home. Toronto plays on artificial turf, which can be tough on the legs.
During his eight-game rehab assignment, Keppinger only played shortstop once and was used mostly at third base or designated hitter. He batted .448 (13-for-29) at Class A Sarasota and Louisville.
"The hard part is getting my muscles back to game shape," said Keppinger, who wore a protective sleeve and a pad on his knee. "The knee is doing all right. It's not the greatest but not the worst. I'll be fine."
Reds manager Dusty Baker and general manager Walt Jocketty made the call after talking with Louisville manager Rick Sweet and Reds Minor League director Terry Reynolds.
"They thought Kepp had shown he was ready," Baker said. "He'll play today and we have a day off tomorrow, which is good. Then he can get some more treatment. We still have to watch him late in the game, in extra innings and on turf [in Toronto]."
Meanwhile, Hairston is set to begin a rehab assignment in Louisville on Monday.
"If everything goes according to plan, I'll meet the team Thursday in Toronto," Hairston said.