NEW YORK (Reuters) - Sidney Crosby has had more of the post-concussion symptoms that bothered him in the spring, but the Pittsburgh Penguins said the center has not had to shut down his conditioning program in his bid to come back.

"The good news is he continues to work out and has worked out hard during the summertime," Shero said in Pittsburgh, according to the league's official website (www.nhl.com).

"When he went back (to Nova Scotia), he has a progression plan with his trainer, Andy O'Brien, which he's gone through, and we'll see where he is during training camp."

Shero would not speculate whether Crosby would be ready for the start of camp or when he might be cleared for contact on the ice. Crosby must be symptom-free before he can resume contact, which is required before he can play in a game.

Playing without Crosby, Pittsburgh was knocked out by Tampa Bay in the first round of the playoffs.

Drafted first overall by Pittsburgh in the 2005 NHL Entry Draft, the 24-year-old Crosby has lived up to the hype and his nickname of "Sir Sidney" as NHL royalty.

Since joining the Penguins for the 2005-06 season Crosby has been a points-producing machine and an NHL Most Valuable Player winner, recording 215 goals and 357 assists for 572 points in 412 regular season games.

(Reporting by Larry Fine in New York, Editing by Rex Gowar)