Center Sidney Crosby has already missed 13 games for the Pittsburgh Penguins with complications due to a concussion, and his return date is still unknown.

Coach Dan Bylsma addressed Crosby's status, as well as other injury news, during practice on Monday.

"The schedule with Sidney, we thought he would return sometime this week. There wasn't a definite date or definite day," he said. "Right now, I haven't had a lot of contact. He's in contact with our trainer just to let him know how he's feeling and so forth. There really isn't a timeframe, as far as we're concerned at this point, of getting him back into town."

Crosby left the team last week to visit his parents outside of Halifax, N.S.

Since he left, not only did Pittsburgh lose to the Washington Capitals, 3-0, on Sunday, the Penguins lost center Evgeni Malkin to two torn ligaments in his right knee. Malkin was injured in the Penguins' 3-2 win over the Buffalo Sabres on Friday. It's still not clear if he'll need surgery.

"Given the severity of the injury, right now we're taking some time to let his knee calm down a little bit, get doctors' opinions and options for what he has going forward," Bylsma said of Malkin. "It's not a lot of urgency, at this point in time, to rush into a certain decision."

Meanwhile, the cloud continues to hover over Crosby, who hasn't played since an 8-1 loss to the Tampa Bay Lightning on Jan. 5. Bylsma was asked Monday about the possibility of Crosby's absence growing even longer than originally thought.

"That really has not been a topic of conversation or a thought. Certainly, when the doctor told us he had a mild concussion, we were expecting this not to last this long and it was certainly our concern about making sure his health is full when he comes back to play," he said. "But really, we haven't gone down a label of time. We certainly want to make sure we go through the necessary steps, and he gets returned to health and he's symptom-free and then progressing toward what the doctor recommends with exercise and so forth."

Another injured center, Mark Letestu, underwent surgery on his left knee, and will miss four to six weeks. Letestu suffered a meniscus injury during morning skate last Tuesday, prior to a 4-3 shootout win over the New York Rangers.

The Penguins play host to the Columbus Blue Jackets on Tuesday. Two more players who missed practice on Monday, forwards Chris Kunitz and Pascal Dupuis, are expected be in the lineup, Bylsma said.