Joe Thornton sat down Monday in his usual space at the Sharks' practice rink. To Thornton's immediate left was the locker of Daniel Winnik, with the team for just a week. To Thornton's immediate right was the locker of Dominic Moore, with the team less than three weeks. At various spots around the room were the spaces of eight other players, none of whom was with the team during the previous four seasons that produced four division titles. They are mixed with the spaces of the players who have been here but are underperforming. Thornton is the captain. This is his crew. And over the next month, he faces his greatest challenge.