Timing is everything for shaky Hasselbeck

Seattle quarterback Matt Hasselbeck has not played well since returning to the lineup after missing more than a month because of a knee injury, and the Seahawks are 3-3 in their last six games heading into the playoffs.

Hasselbeck has thrown eight passes that were intercepted since coming off the injured list and threw for only two touchdowns in the last three regular-season games. Not the type of momentum the Seahawks were looking for as they try to repeat as NFC champions.

Compare Hasselbeck’s performance this season -- 2,442 yards and 18 touchdowns with 15 interceptions in 12 games -- to last season when he ranked among the top quarterbacks in the league with 3,459 passing yards and 24 touchdowns with nine interceptions.

Hasselbeck’s main problem has been his timing, which can be attributed to his injured knee and Seattle’s revamped group of wide receivers. The Seahawks’ wideouts, featured heavily in Coach Mike Holmgren’s multiple-look offense, have been hampered all season because of injury or illness.

While Bobby Engram has returned after missing several games because of a thyroid condition, leading receiver Darrell Jackson (toe) and upstart D.J. Hackett (hip flexor) are listed as questionable for Saturday’s game against Dallas.

That’s bad news for Hasselbeck, who has looked shaky in the pocket since his injury. Hasselbeck is at his best when he’s passing to a variety of receivers. But if he’s without Jackson and Hackett, that puts more pressure on players such as Deion Branch, Nate Burleson and Engram.

Seattle can help Hasselbeck by giving the ball as much as possible to running back Shaun Alexander, who has run hard since missing six games because of a foot injury.

His value isn’t difficult to quantify: Seattle is 29-6 when Alexander rushes for 100 yards or more and is 23-2 when he rushes for at least two touchdowns.

Although Alexander has topped 100 yards only twice since his return, whatever production his running brings gives a big boost to the passing game.

Behind a banged-up offensive line -- the availability of starting guards Chris Gray (quadriceps) and Floyd Womack (groin) will be game-time decisions -- Hasselbeck will have to be at his best against the Cowboys.

But Hasselbeck has been here before and he knows how to lead the Seahawks in the playoffs. Look for him to bounce back on Saturday by getting the ball to tight end Jerramy Stevens and exploiting single coverage in the Cowboys’ secondary.

lonnie.white@latimes.com