The Red Devils’ new boss Ole Gunnar Solskjaer has won his first seven games in the hot seat.
One big change he made to the squad was removing Lukaku, who joined the club for £75m in 2017, from the starting line-up.
The Norwegian put Marcus Rashford in his place as the forward has only nine goals this season.
And Cole, who scored over 120 goals in eight seasons at Old Trafford, told BBC Radio 5 Live what the Belgian should do.
“He needs to play to his strengths, which are pace and power”
“Basics,” Cole said.
“He’s got to go back to basics.
“When you play for Man United, you haven’t got a weekend off.
“I’m not being disrespectful to Everton or West Brom but when you’re at those football clubs you can.
“When you’re at Man United you’re expected to score goals.”
The 47-year-old went on to say that Mourinho’s management did not help the forward.
Cole added: “Playing under the previous manager didn’t help because there was no creativity in the team, so he wasn’t getting many chances.
“He was trying too hard and that’s a problem if you’re a centre-forward.
“If he comes in, he should play one-touch.
“He needs to play to his strengths, which are pace and power.”
This comes as chief executive Ed Woodward has been told he must sign a centre-back.
And a former Premier League player has said Alexis Sanchez can get United into the top three.