SAN FRANCISCO — The San Francisco Giants could be back to their patchwork pitching rotation of recent years.

Left-hander Noah Lowry was forced to leave his start Thursday against the Atlanta Braves in the second inning with a strained muscle in his lower back.

The severity of the injury wasn't immediately known. The 25-year-old Lowry, the Giants' No. 3 starter, was undergoing tests and scheduled to be re-evaluated Friday.

"I don't know how serious it is," trainer Stan Conte said after the Giants' 6-4 win in their home opener. "We're still in the midst of it. We'll know more tomorrow afternoon."

MARINERS ACQUIRE DE LA CRUZ: The Seattle Mariners acquired Class A pitcher Jose De La Cruz from the Tampa Bay Devil Rays on Thursday for Marcos Carvajal in a swap of right-handers. The 22-year-old De La Cruz was 3-6 with a 3.94 ERA and 19 saves in 50 games for Class-A Southwest Michigan in 2005. The Devil Rays signed him in 2002. Seattle had designated 21-year-old Carvajal for assignment last week. He allowed eight runs in 2 1/3 innings during spring training.

YANKEES CLAIM HILL: The New York Yankees claimed catcher Koyie Hill off waivers from the Arizona Diamondbacks on Thursday. New York, which already is carrying three catchers, must make a roster move when Hill reports to the team. If Hill is put on the 25-man active roster, Wil Nieves appears likely to lose his spot.

BURNETT MAKES REHAB START: Toronto's A.J. Burnett allowed one run and three hits in four innings Thursday night during a rehabilitation start for Class A Dunedin against Clearwater in Florida. Burnett walked two, struck out two and hit a batter, throwing 39 of 62 pitches for strikes. The right-hander, signed to a $55 million, five-year contract during the offseason, took himself out of a spring training game on March 18 because of elbow pain, which came from scar tissue coming loose. Toronto has said Burnett will make another rehab start on April 11, then make his Blue Jays debut at the Chicago White Sox on April 16.