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."
Asked if Harrison would return to the Steelers on Thursday or even at all this week, Parise said, "I sure hope so."
Harrison said Tuesday on Fox Sports Radio's "Into The Night with Tony Bruno" that he might consider retirement.
"I'm going to sit down and have a serious conversation with my coach tomorrow and see if I can actually play by NFL rules and still be effective," Harrison told guest host Judy McDonald. "If not, I may have to give up playing football."
Harrison was not penalized on the plays that resulted in Massaquoi and Josh Cribbs leaving the game with concussions.
The hit on Cribbs was deemed a legal hit because Cribbs, running out of the Wildcat formation, was a runner in possession of the ball. Harrison's headfirst hit of Massaquoi during a pass attempt drew the fine.
"I really truly hope it's something that can be done," said Harrison, a three-time Pro Bowl selection who was named The Associated Press' defensive player of the year in 2008. "But the way that things were being explained to me today and the reasoning for it, I don't feel I can continue to play and be effective and, like I say, not have to worry about injuring someone else or risking injury to myself."
Massaquoi's agent, Brian Ayrault, didn't think the league was tough enough on Harrison.
"Harrison has made $20 million over the past three years, and they only fined him $75,000?" he said. "To me, that's not going to be a deterrent. The Browns are probably going to be without a starter this week. I don't think that fine is a deterrent or fair to competitive balance.
"The punishment did not fit the crime."
Adam Schefter is ESPN's NFL Insider. Information from The Associated Press was used in this report.