Rahman has not been overly impressive after joining the London giants, necessitating a loan move to Schalke 04 last season.
"He still has to continue to train hard and must be strong. Many footballers coil in their career when things doesn't go well.
"But instead of keeping his shin down, he must keep it up and continue to work hard to wait for his opportunity and make good use of it, " Njitap told the press during the FIFPro Africa Division Annual Congress in Accra.
From Sammy Heywood Okine