Manchester United manager Sir Alex Ferguson has confirmed that the Football Association has asked his club to file a report on a post-match brawl at Stamford Bridge on Saturday.
The incident occurred when the United substitutes were warming down after the 2-1 defeat to Chelsea and they became embroiled in a scuffle with some members of the home side's groundstaff.
United's French defender Patrice Evra was believed to have been at the centre of the fracas and will give his account of the incident to club officials on Monday.
Ferguson said in the build-up to Tuesday's vital Champions League game with Barcelona: "We're filing a report which will be sent to the FA.
"We're very happy with that, we're delighted with that. We hope the FA investigate it."
The problem arose when Evra, Gary Neville, Paul Scholes, John O'Shea, Park Ji-Sung and Gerard Pique were asked to run up and down the Stamford Bridge pitch instead of across it, which led to a scuffle breaking out.
In a separate post-match incident a female steward has accepted Rio Ferdinand's apology after the England international caught her while kicking out at a wall in frustration.