He told fulhamfc.com: "We've signed Shefki until Christmas time and I've said to him it's a chance for him. His career was going quite well at Blackburn and then after a £2.5m move to Palace he found himself out the team.
"He's a bull of a man and it was no great secret that we were trying to sign some centre forwards to compensate for the loss of Brian McBride. Shefki was offered to us for three months and he can fill that role for us.
"Where it's gone wrong at Palace I don't know and we'll have to see if he can do the business here. It's a great chance for him to prove himself."