His teammates learned that strange truth over the past three weeks. It's why they eagerly await his return to the lineup tonight against San Jose in Nationwide Arena.

"You don't always think about Jan out there, and I mean that in a good way," Jackets captain Rick Nash said. "He's always in position and never making mistakes. You don't notice him until he's gone, and then you realize how good he really is."

The Jackets were 4-1-0 with a 2.20 goals-against average when Hejda suffered a sprained left knee Oct. 13 against Calgary.

In his absence, they went 3-4-1, surrendering 4.25 goals per game and squandering four third-period leads.

There were other contributing factors to the skid: poor puck management by forwards, a couple of shaky outings from goaltender Steve Mason and two energy-sapping trips to the West Coast in a 20-day span.

But Hejda's reliable play in the face of the opposition's best forwards has been sorely missed.

Even teammates who frequently acknowledge Hejda's unsung contributions have gained greater appreciation for his game.

"It was nice to hear," Hejda said. "(Mason) told me after they'd got back from the last Canada trip he doesn't want to play unless I'm on the ice."

The 6-foot-3, 229-pound defenseman is returning more than a week earlier than projected. He spent five hours a day rehabbing his knee.

Skating against the Sharks beats swimming with injured teammate Fredrik Modin.

The Jackets will have their top two defending defensemen in the lineup for the first time this season. Mike Commodore missed the first eight games because of a pulled groin muscle.

Coach Ken Hitchcock isn't sure how he will sort his pairs, but he knows Hejda's presence will relieve heavy minutes from some overworked defensemen.

Matching Hejda, a plus-51 in his two-plus seasons with the Jackets, against the likes of San Jose's Joe Thornton and Atlanta's Ilya Kovalchuk also gives Hitchcock comfort.

"Jan defends the other team's top players, and when you can't defend the other team's top players, you are constantly on edge," Hitchcock said.

Following the Jackets' 5-4 overtime win over Washington on Sunday, Hitchcock cited Hejda in talking about his team's inability to hold leads.

"Until we get the big guy back there and it starts to spread out the minutes, we will have trouble because we're running out of gas," Hitchcock said.

Hejda performs a catalog of selfless tasks, including blocking shots, clearing the front of the net and angling the opponent's most dangerous forwards to the perimeter.

Those abilities are especially valued when the Jackets are short-handed. The Jackets' penalty kill, clicking at 94.7 percent with Hejda in the lineup, was 71.7 percent in his absence.

"He's a big body, he clears guys out of the way for us," Mason said. "For a goaltender, you like having him on the ice, and we're looking forward to having him back."

Hejda said it will take about three games to regain his conditioning and top form. The Jackets will be happy to just see him in the lineup instead of the pool.

treed@dispatch.com