The Pittsburgh Steelers excused James Harrison from practice Wednesday as the Pro Bowl linebacker contemplated retirement, according to his agent.

Harrison's agent Bill Parise said Wednesday his client is "very serious" about retiring after getting fined $75,000 for a hit that knocked Mohamed Massaquoi out of the Steelers' win over the Cleveland Browns. Harrison met Wednesday with Steelers coach Mike Tomlin, who excused his linebacker from the Steelers preparations for Sunday's game against the Dolphins.

"We wouldn't joke about this," Parise said. "This is a very serious issue. James is very concerned about how to play football. If James is going to be fined $75,000 for making a legal tackle, then how do you go play football? It's quite frustrating to James, to Coach Tomlin, to me, to everybody."

Asked how real these retirement threats were, Parise said, "We're working very hard to make sure that we make good decisions."

Tomlin said he expects Harrison to return to practice on Thursday.

"We had a meeting this morning, he and I did. It was a very productive one," Tomlin said in a conference call with Miami reporters. "I thought part of being productive and moving forward was excusing him for today and coming back starting new tomorrow."