Is 49ers' championship window closing?

Colin Kaepernick and Jim Harbaugh have been one of the NFL's most successful QB-coach tandems. Christian Petersen/Getty Images

A high-ranking NFL personnel evaluator I ran across at the NFL scouting combine Thursday morning said he was hearing sensational stories about the San Francisco 49ers. He would not elaborate because the stories were unsubstantiated, but we can assume at least one of them found its way into the news over the weekend.

There is sensational, and then there is trade-the-head-coach sensational. Harbaugh to the Cleveland Browns by trade? The 49ers initially denied ever discussing such a transaction. The Browns issued a non-denial before their owner, Jimmy Haslam, confirmed that such discussions took place. The particulars matter less at this point than the gathering idea that Harbaugh might not be part of San Francisco's longer-term future. It's no secret that Harbaugh and the team's executives have been unable to make progress toward a contract extension amid rumblings of friction.

Here are the questions: Could the 49ers remain a contender without Harbaugh? And is their championship window closing regardless?