Jeff Karstens was hit in the knee by Julio Lugo's line drive on his first pitch, then came out after giving up a single to Kevin Youkilis. The right-hander was replaced by Kei Igawa, relegated to the bullpen after flopping in his most recent start Monday night against Tampa Bay.

It was the latest injury to New York's depleted staff. Already missing starters Mike Mussina (hamstring) and Carl Pavano (forearm), the struggling Yankees sent Karstens to the mound hoping he could help end a seven-game skid _ their longest since the last week of the 2000 season.

He lasted only six pitches. Lugo's hard liner hit Karstens on the side of his right knee, and the rookie crumpled to the ground in pain as Lugo reached first with an infield single for the Red Sox.

A trainer and manager Joe Torre came out of the dugout to check on Karstens, who stayed down for several moments before getting up and trying to walk it off. He received a huge hand from the crowd, threw a few warmup pitches and remained in the game.

But Karstens, who began the season on the disabled list with tendinitis in his right elbow, fell behind 3-1 on Youkilis and gave up a sharp single to left. Torre popped out of the dugout again — with a trainer, again — and signaled for Igawa. Wearing sunglasses on a cloudy afternoon, the left-hander was given as much time as he needed to warm up.

Igawa escaped the first inning without any damage. On his second pitch, the rookie got slugger David Ortiz to ground into a double play. After a walk to Manny Ramirez, Igawa struck out J.D. Drew with runners at the corners.

Igawa got Ortiz to ground into another double play in the third, ending the inning.

The Yankees spent $46 million to bring Igawa over from Japan, but he has been inconsistent in four starts. He began the day 1-1 with a 7.84 ERA and nine walks in 20 2/3 innings.

Beset by injuries to its top pitchers, New York recently got Chien-Ming Wang back from the DL. Wang, a 19-game winner last season and runner-up for the AL Cy Young Award, is scheduled to make his second start of the season Sunday in the series finale against Boston.