(Reuters) - Regular referees will be back in action after a deal was struck to end their lockout ahead of Thursday's game between Baltimore and Cleveland, with the Browns now likely to be more concerned with Ravens quarterback Joe Flacco than the officiating.

National Football League referees have dominated headlines since the widely criticized touchdown call on the final play of Monday's primetime game between the Seattle Seahawks and visiting Green Bay Packers.

Baltimore's Flacco had been among the most outspoken players on the issue of the replacement referees, saying last week that they were "affecting the integrity" of the game.

However, following a breakthrough deal between officials and the league on Wednesday, Flacco's ability to run the Ravens offense will represent the biggest obstacle for winless Cleveland heading into the AFC North division clash.

In Sunday's dramatic 31-30 win over the New England Patriots, Flacco threw for 382 yards and three touchdowns while looking increasingly comfortable in a no-huddle offense.

"I've always been a Joe Flacco fan," Browns coach Pat Shurmur said on Tuesday. "I always thought he's been a good quarterback, a top-level quarterback in this league."

While the focus with the Ravens is so often on their bone-crunching defense, Shurmur said he was not surprised at all about the form of Flacco and the Ravens offense this season.

"Someone was trying to kind of council me up about Joe Flacco, if he's taken the next step? I mean you're looking at a quarterback that's led his team to the playoffs the last four years," Shurmur said.

"They have (running back) Ray Rice, they've got a veteran receiver in Anquan Boldin and then Torrey Smith. They've got some outstanding players and they're playing extremely well.

"When you watch them play I think they've made an effort to become more explosive as an offense and I think that's showed up in the first three weeks."

The Browns are relying largely on two rookies - quarterback Brandon Weeden, who has six interceptions and three touchdowns from his opening three weeks, and running back Trent Richardson - to cope with the threat of a defense featuring 13-time Pro Bowl linebacker Ray Lewis and eight-time Pro Bowl safety Ed Reed.

Ravens defensive coordinator Dean Pees is particularly impressed with Richardson's rushing.

"Richardson is everything that everybody talked about in the draft and coming out of Alabama. The guy is physical, he's strong. He's never going backwards. He's always falling forwards," Pees said.

"You get in a short-yardage situation, he's really exceptional. He is an exceptional, exceptional back. He's going to be something to deal with for probably a long, long time."