Harrison was so upset with the fine -- and the NFL's stricter punishment of dangerous hits -- that he said he was weighing retirement, although Tomlin expects his star linebacker to practice Thursday.
"I thought it was beneficial for him and for us if I gave him a little time to cool off and give him the day off," Tomlin said. "I excused him at that time, and we went on and had a productive day. I'm sure he will be back in the building tomorrow."
Harrison said in multiple radio interviews that he isn't certain that he can keep playing the way he has been taught now that the league not only is fining players, but is threatening to suspend them for flagrant hits. Harrison was fined $5,000 earlier this season for a hit on Tennessee Titans quarterback Vince Young. Neither of the Harrison hits that drew fines this week was penalized.
"How can I continue to play this game the way that I've been taught to play this game since I was 10 years old?" Harrison said on Sirius/XM radio. "And now you're telling me that everything that they've taught me from that time on, for the last 20-plus years, is not the way you're supposed to play the game any more? If that's the case, I can't play by those rules. You're handicapping me."
The three-time Pro Bowl outside linebacker also said he might retire, although the Steelers don't seem to be taking that threat seriously. If he quit, Harrison would owe the Steelers a share of the $20 million in upfront money he collected when he signed a six-year, $51.2 million contract in April 2009.
Harrison was fined, but not suspended, for the hit on Massaquoi because the receiver couldn't protect himself as attempted to complete a catch. Harrison appeared to launch himself toward Massaquoi and struck the receiver with his helmet.
After reviewing the hit on Cribbs, the NFL gave Harrison a half-sack since the receiver was lined up at quarterback and didn't gain any yardage. LaMarr Woodley received the other half-sack.
Tomlin repeated Wednesday that he is convinced Harrison's hit was permissible.
"This is a very emotional thing for James," Tomlin said. "He's a very disciplined and regimented guy who's passionate about the game of football. It bothers him maybe that he's being perceived as a dirty player. He doesn't desire to be. He simply wants to play the game and play it extremely well."
After the game, Harrison said he tries to hurt opposing players because it helps the Steelers win, although he doesn't try to injure players. Tomlin wouldn't speculate if those comments might have led the NFL to increase its fine. Harrison has since backed off those comments, saying he doesn't try to injure anyone.
The absent Harrison received considerable support from his teammates, with guard Chris Kemoeatu saying the linebacker's relentless attitude motivates the offensive players, too.
"He is a really big influence to us," Kemoeatu said. "We look up to him, and we see his style of play, and we want to be like him and hit like him and run like him. I don't know how he's affected by it, but I know he's disappointed. I think he's going to work things out, and I think he will be all right.
"I'd love to for him to retire," said Brady, who plays Nov. 14 in Pittsburgh. "If he retired, it would make me very happy."
The Associated Press contributed to this report.