"As Tony Sparano maintains his tenuous grip on the Dolphins' coaching job, it is becoming clear he may have to make changes that go beyond staff and player personnel even if he is retained for 2011.

A series of critical comments from current and former Dolphins, most notably all-time franchise greats Ricky Williams and Jason Taylor, have raised doubts about Sparano's ability to create a positive and productive workplace.

It was Williams, expected to leave as a free agent after six full seasons with the Dolphins, who started the public debate with Monday's radio comments about Sparano's "micromanaging" style.

Wednesday, also speaking on WQAM-560, Taylor took a break from playoff preparations with the Jets to lend considerable heft to Williams' concerns.

"I played for Tony for one year [2009] in that kind of system and atmosphere. It's tough," Taylor said on The Joe Rose Show. "What Ricky was saying is true in a lot of senses. It's a tough work environment. … The micromanaging and things like that are exhausting."

Meanwhile, Stanford coach Jim Harbaugh reportedly interviewed with the San Francisco 49ers on Wednesday afternoon in the Bay Area.

A source said Tuesday that the Dolphins had begun exploratory discussions with Harbaugh about becoming their next coach, but the 49ers have been targeting him as Mike Singletary's successor for at least the past few months."