Fulham launched an official complaint to the Premier League on Thursday over Liverpool's conduct in their pursuit of American forward Clint Dempsey.
Liverpool boss Brendan Rodgers last month broke managerial protocol when he went public with his interest in Dempsey, prompting the Cottagers star to make it clear he wanted to move to Anfield.
But there has been no firm bid from Liverpool since then, leaving the player confused and Fulham boss Martin Jol furious.
Jol has left Dempsey out of his squad for Saturday's trip to Manchester United, having already dropped him for last weekend's victory over Norwich because he felt the player wasn't in the right frame of mind to perform.
The Dutchman criticised Liverpool's behaviour last week and the west London club have now followed up with a complaint to the Premier League.
"The Premier League has received a complaint from Fulham regarding certain comments made by Liverpool officials and is currently looking into the matter," a statement read.
Jol is frustrated that he has been left with an unsettled player, but has offered an olive branch to Dempsey, who was his side's top-scorer last season.
"Mentally Clint wants to move, he doesn't want to stay here. His head was turned and that was the problem," Jol said on Thursday.
"It's a problem and a situation you don't want. It's not something you can talk to a player about every day because he doesn't want to.
"I don't know if he'll remain a Fulham player. I'd love to keep him, but I'm not sure.
"Hopefully if he stays, then in the next couple of weeks he will change his thoughts about us.
"With me there's no problem and I don't think there's a problem within the team over him."
Jol denied Dempsey had refused to play for Fulham again, instead declaring it was his decision to drop the 29-year-old, who has entered the final year of his contract.
"I never said he's gone on strike," he said. "It started during our pre-season tour to Germany. I was probably a bit naive, asking 'Clint, do you want to start?'. All he said was 'you know what I want'.
"This hasn't caused any disruption to the squad because of the decision I made in Germany not to play him.
"After that it was very difficult to communicate. He was not committed to the team.
"For us it would have been better had Liverpool followed it up with a formal bid, but they haven't."