Doncaster Rovers assistant manager Richard O'Kelly believes Mustapha Dumbuya is a "long way" from being the finished article despite his impressive displays against Norwich and Leeds Dumbuya, contracted to the club until the end of the season, is expected to keep the right-back spot for the third match in succession when Rovers travel to top-of-the-table QPR at the weekend.The pacy defender, who made just three appearances last term, starred in pre-season friendlies against WBA and Sheffield Wednesday, earning high praise from manager Sean O'Driscoll.O'Kelly said Dumbuya "really stepped up to the plate" over the summer period and that he is encouraged by his development.But O'Driscoll's chief lieutenant is urging Dumbuya to keep on improving his all-round game."Mustapha is a long way away from being the finished article,""Like any player, if you start to listen the plaudits coming your way you can become complacent."Mustapha has got a long way to go but in the two games he has played he certainly has not done his case any harm."In pop music, you have one hit wonders and in football sometimes you have one season wonders."He has started very well but the trick as a professional footballer is to do it day in, day out. He has got to keep on coming to training to try and improve himself and then going out and playing the game becomes second nature."Dumbuya arrived at the Keepmoat Stadium last August, having previously represented non-league clubs Wingate & Finchley and Maidenhead United.He also had trials and trained with Grays Athletic, Gillingham, Hereford United and Premier League outfit Fulham."We are big on the personality and the character of the person we bring to the football club," said O'Kelly. "We don't always get it right but any person who signs a contract and comes through the door at Doncaster Rovers needs to be the right character, personality and want to improve and do things the way we do."When Mustapha first came to the club we thought that he had all those qualities so hopefully he can keep going from strength to strength."Meanwhile, James Hayter is set to return to full-training come the end of the week. The striker, who was a guest summariser for Sky in the 0-0 draw with Leeds, has almost recovered from a hamstring injury. But O'Kelly says Hayter is unlikely to be considered for the trip to Loftus Road.