In 2003, after only three weeks since signing for Millwall, Muscat was fined and reprimanded by Millwall after a match against Watford where he gave away a penalty and was sent off for stamping on Watford's Danny Webber. Millwall chief executive, Ken Brown, formally warned Muscat that he would be sacked if he did not "clean up his act." "Kevin's actions were totally unacceptable. We have made him aware that such behavior will not be tolerated. Any repeat of such a deliberate, unprovoked, off-the-ball incident will result in his instant dismissal."