"There's no doubt that they're the most in-form pairing at present, so I think now is the time to see if they can develop into a decent strike force," he said.
"Saturday's match against Sunderland was only the third time they've started a match together in the Premier League, and there were one or two signs that they could flourish.
"But the fact is we will never know unless we give them a chance to gel."
