It cost him 12 weeks and reduced the velocity on his pitches, and that's why he dropped from a potential top-10 pick to 40th overall.
That's one factor why the A's decided to be cautious with their second-year closer and put him on the disabled list before Sunday's 6-4 win over Kansas City. Street left the second game of Friday's doubleheader with a strained groin.
"It's definitely really sore," Street said. "For me to pull myself out of a game, it's going to be pretty bad."
The only way the A's wouldn't have made the roster move is if Street felt dramatically better Sunday, which he didn't.
"(Street) is a young player, a max effort guy," A's trainer Larry Davis said. "It's his push-off leg. You can't expect him to compensate for that. He would end up hurting his arm. It's the prudent thing to do."
Street was scheduled to fly home to Oakland after Sunday's game to get an MRI on Monday.
Davis said it's a Grade I strain, the least severe, which normally requires seven to 10 days to heal. He also said Street would be "darn close" to ready when the 15 days are up.
REPLAY: Jay Payton doubled home two runs in a three-run first inning Sunday against Kansas City, including Frank Thomas' first run scored from first base on a double this year. Eric Chavez and Mark Kotsay hit sacrifice flies as the A's built a 4-0 lead after two innings.
Kirk Saarloos (6-6) recorded six consecutive outs via groundballs to begin the game, and 14 of his 18 outs came on grounders, including two double plays. Joe Kennedy pitched two scoreless inning of relief.
Nick Swisher hit a two-run home run in the eighth inning, which was needed since Mark Grudzielanek hit a two-run, inside-the-park homer off Justin Duchscherer with two outs in the ninth.
CF Mark Kotsay saw his career-high, 16-game hitting streak end in the second game of Friday's doubleheader, when he entered defensively in the ninth inning and made an out in his only at-bat. He's hit in 18 of his last 19 games, including a first-inning double in Sunday's game. Kotsay also had his second assist in as many games, extending his total to 104 since 1998, the most in the majors among outfielders in that stretch.
LHP Ron Flores was recalled from Triple-A Sacramento to take RHP Huston Street's place on the roster. It's the fourth time this year Flores has been called up, and he said, with a laugh, he's racking up the frequent-flier miles.
LHP Brad Halsey is the scheduled starter for Tuesday's game. Since Halsey is in the minors now, another roster move will need to be made prior to the game.
3B Eric Chavez didn't improve on his 4-for-56 stretch with runners in scoring position in the first inning Sunday, but he did hit a sacrifice fly to give the A's a 1-0 lead.
C Landon Powell, the A's first pick in the 2004 draft who missed last year with knee surgery, was promoted from Class A Stockton to Double-A Midland. Powell hit .264 with 15 home runs and 47 RBIs for Stockton.
BY THE NUMBERS: 15 -- The number of scheduled doubleheaders the A's had in a bizarre 1971 schedule.
QUOTE TO NOTE: "They're terrible. It can really ruin your month. If you go 0-for-8 or 0-for-9, it tears up your whole week. They aren't any fun. It takes a lot to get geared up for two games in a row." -- A's designated hitter Frank Thomas, on doubleheaders.