Juan Rivera Has Ruptured Hamstring Muscle

Dodgers outfielder and first baseman Juan Rivera was placed on the disabled list with a serve strain of his left hamstring on Wednesday, but the injury could keep him out much longer than a 15-day disabled list stint.

Rivera has a ruptured semitendinosus, which is one of hamstring muscles that attaches right below the knee. Dodgers trainer Sue Falsone explained the difference between a strain and a rupture.

"Any type of a strain is a tear. It's just to what degree. Sprains are typically graded one, two, or three, with grade one meaning some fibers of the muscle are torn. Grade two, a little bit more are torn. With a grade three, the muscle is torn through," Falsone said. "A rupture is like a grade three plus."

Falsone added that the hamstring strain for Jerry Hairston Jr., who was placed on the disabled list on Friday, is closer to a grade two strain.

The actual tendon that Rivera tore is the same one used in Tommy John surgeries. Even though the tendon isn't necessarily needed, the worst case scenario for recovery is six to eight weeks for Rivera.

"There aren't a lot of these documented. There is one really good study, but even that only has 25 people and it's not all baseball players. Some are hockey players and some are football players," said Falsone. "Because a full rupture doesn't happen very often, we don't have as clear of an idea of how long it takes to get back."

Falsone said Rivera will be reevaluated in two weeks, and its possible he could return to the team shortly after that, but it really depends how he responds to treatment. Rivera exercised Friday and rode a stationary bike pain free.

Falsone and the Dodgers medical staff has consulted with physicians throughout the country for this injury that is relatively rare to baseball. In some cases, surgery has been needed to clean up debris in and around the rupture, but it is not yet clear whether or not Rivera would need that procedure.

Struggling Gordon

Dee Gordon went 0-for-5 on Wednesday to end his eight-game hitting streak, and on the season is hitting just .227/.268/.294. But manager Don Mattingly remains committed to his leadoff hitter.

"I believe in what Dee is capable of, that's for sure. Dee is going to be fine. I don't have any doubt about it," Mattingly said. "That doesn't mean we don't have conversations about getting him to relax and getting him to be himself."

Mattingly had one of those conversations with Gordon on Friday, in which he tried to get the speedy Gordon to slow things down (I immediately thought of Jerry Seinfeld: "Sex to save the friendship!").

"When he gets on base, he wants to go right away, instead of going at the right time, picking his spot and when he's supposed to be going," Mattingly said. "You can't get time back. You can't get four hits in on at-bat. You can only have good at-bats."

Roster Move

Before Friday's game, the Rockies optioned Drew Pomeranz to Triple A Colorado Springs, and recalled reliever Josh Outman. Pomeranz was tentatively scheduled to start Sunday, but that assignment will now go to Alex White, who the Dodgers drafted in the 14th round but did not sign in 2006.

Starting Lineups

Game Time: 7:10 p.m.

TV: Prime Ticket

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