DENVER -- Rockies shortstop Troy Tulowitzki has a complete tear of a tendon in his left quadriceps and could be out until the All-Star break or longer, according to his agent.
Paul Cohen, Tulowitzki's California-based agent, said in a phone interview on Thursday that the best-case scenario for Tulowitzki is that he could be back "as early as six weeks, but it's possible it could take a couple of months or more." Cohen said more will be known after further examination this weekend.
The Rockies have not released any information on Tulowitzki's injury. The team was off on Thursday, so a statement could be made on Friday when the team plays the Dodgers at Coors Field.
The injury, suffered during the first inning of Tuesday night's game against the Giants at AT&T Park, brought Tulowitzki's difficult first month to a painful end.
The runner-up in last year's National League Rookie of the Year voting, who signed a six-year, $31 million contract during the offseason, Tulowitzki has hit .152 with one home run and 11 RBIs in 105 at-bats this season. He was 4-for-40 and 0-for-12 in three games before the injury.
The Rockies' No. 1 Draft pick in 2005 (seventh overall), Tulowitzki, 23, batted .240 in a 25-game trial in 2006, then won the shortstop job before last season and hit .291 with 24 home runs and 99 RBIs.
The injury means Clint Barmes, the starter from 2005 until Tulowitzki emerged, returns to his old job. After spending much of last season at Triple-A Colorado Springs, Barmes won a utility job this spring, but took over at second base when rookie Jayson Nix struggled and had to be sent to Colorado Springs. Through 19 games this season, Barmes is hitting .240 with two home runs, six doubles and nine RBIs.
Barmes was the Tulowitzki of the first 54 games of 2005 -- a prime NL Rookie of the Year candidate. Barmes was hitting .329 when he suffered a broken collarbone in a fall away from the park. Barmes hit just .216 after returning and .220 in 2006 before losing his job. A more seasoned Barmes moves into Tulowitzki's spot.
"I don't like the word 'relaxed' -- I'm relaxed as far as mentally, but I am not relaxing when it comes to work," Barmes said. "But mentally, this is the best I've been, offensively and defensively."
Jeff Baker, who has missed recent action with a broken blood vessel in his right middle finger, and two players called up Wednesday, Omar Quintanilla and Jonathan Herrera, will share second base. Quintanilla and Herrera also have extensive experience at shortstop and can back Barmes.
Thomas Harding is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.