Red Sox starter Daisuke Matsuzaka receives a welcome from manager Terry Francona after the top of the second inning.

The Providence Journal / Bob Breidenbach

BOSTON — To adapt a sporting world cliché, he is what he is.

Anyone expecting Daisuke Matsuzaka to be anything but a six-inning pitcher has been disappointed and will continue to be disappointed, because in his almost two seasons in Boston, Dice-K has done nothing to indicate he can be anything but a six-inning pitcher, maximum.

Matsuzaka is a solid pitcher. At least, he’s able to limit any damage, which is why he is 12-2 with a sterling 3.04 earned-run average after Boston’s 5-2 series-sweeping win over Oakland at Fenway Park yesterday.

He is stingy when the opposition puts runners in scoring position. That may be his biggest strength.

Yesterday offered yet another perfect illustration of Dice-K as a Red Sox pitcher.

Oakland’s Carlos Gonzalez led off the second inning with a triple to center. Boston was on top, 1-0.

Matsuzaka, though, stranded Gonzalez at third. He whiffed Jack Hannahan and Bobby Crosby and retired Daric Barton on a fly ball to shallow center.

But, in keeping with his history of abbreviated outings because of high pitch counts, it took Matsuzaka 23 pitches to get those three outs, inflating his two-inning total to 43 and pushing him along the path to a sixth-inning exit.

Matsuzaka fanned eight, and strikeout pitchers tend to throw a lot of pitches. Dice-K, though, rarely gets any three-pitch whiffs. Yesterday Matsuzaka needed 10 pitches for one punchout, seven pitches for another, six pitches for four strikeouts and one each at five and four pitches.

The generally youthful Athletics, who are last in the league in batting average (.246) and first in the league in strikeouts (831), were able to foul off numerous pitches before Matsuzaka was able to put them away.

He faced 23 batters, and only five of those at-bats ended in either one or two pitches, including Barton’s first-pitch two-run homer in the fifth.

The rain delay cost Matsuzaka any chance of returning for the seventh inning, but he wasn’t likely to be going back out for another inning, anyway. He had thrown 105 pitches for the 18 outs, and manager Terry Francona pulled him after the delay.

An instant hit

Jason Bay’s charmed existence continued in his third day with the Red Sox.

In the first inning, Oakland’s Mark Ellis hit a hard grounder past Mike Lowell and inside the third-base bag. The ball missed the corner of the stands that jut out down the line and kept rolling, seemingly headed for the corner.

Bay, playing left field, began running toward the corner, the play looking like your basic stand-up double.

Suddenly, though, the ball hit the low wall in foul territory at such an uncharacteristic angle that it shot out toward Bay. He scooped up the ball and threw to second baseman Dustin Pedroia. The ball was waiting in Pedroia’s glove when a surprised Ellis slid in, a dead duck for the second out of the inning.

Bay was given a loud ovationfor his first assist as a member of the Red Sox.

Switching sides

Jason Varitek began the at-bat as a left-handed hitter. He ended it as a right-handed hitter.

The unusual circumstance arose in the sixth. Varitek was facing right-hander Joey Devine. The count went to 3 and 2 when the umpires pulled the teams off the field because of thunder, lightning and rain.

When play resumed , Devine had been replaced by left-hander Alan Embree, moving the switch-hitting Varitek to the right side. Varitek swung and missed Embree’s first pitch for a strikeout.

Embree got credit for a one-pitch strikeout. Had Embree thrown ball four, the walk would have been charged to Devine.

Off the mark

The Athletics are young and prone to making mental mistakes.

They did not play fundamental baseball this weekend. Yesterday center fielder Ryan Sweeney was guilty of another one in the first inning. With Pedroia at second base and none out, Kevin Youkilis ripped a single to center.

Sweeney charged the hard hopper and got to it in medium deep center. He had no chance to throw out Pedroia at the plate, but he threw home anyway. That was one mistake. Compounding that mistake was the fact he threw the ball over the head of first baseman Barton, serving as the cutoff man on the mound.

The alert Youkilis rounded first base aggressively and took off for second when he saw the throw going over Barton’s head. Sweeney’s play gave Youkilis an extra base and didn’t keep the double play in order.

skrasner@projo.com