Mpenza has been dogged by a series of injuries and illnesses since joining Argyle as a free agent. He is the club's highest earner being paid a reported £10,000 a week.The club are to send Mpenza for a scan to determine the severity of his latest injury.He joined the club on a free transfer in the summer having previously played for the likes of Manchester City, Hamburg and Standard Liege, as well as winning 52 caps for Belgium."Emile and I have had a discussion about things because obviously services rendered have been very few games for the amount of money we're paying him."We've got to sit down and have a real think about things again. Depending on how long this is going to be we have to make sure it's right for the football club."