That is according to talkSPORT host and transfer expert Jim White.
Fellaini has played just three minutes in Ole Gunnar Solskjaer’s first five Premier League games in charge of Manchester United.
The midfielder was a favourite of former United boss Jose Mourinho, making 19 appearances this season before the Portuguese was sacked in December.
But White claims Fellaini will be allowed to leave on loan this month as he is not part of Solskjaer’s plans.
Scotland international Scott McTominay, who has played just one minute in the league under Solskjaer, will also be allowed to seek a loan move.
“It’s now become apparent Marouane Fellaini can go amid talk that Solskjaer is none to happy with his attitude,” White said on Monday morning.
“Fellaini has been on the outside looking in since Mourinho departed the scene.
“And it’s my understanding this morning he could go on loan in this window, and so might McTominay.
“But it’s clear that Fellaini, specifically Fellaini, is on borrowed time.”
Manchester United beat Tottenham 1-0 on Sunday at Wembley to make it six wins from six for Solskjaer in all competitions.
Solskjaer was full of praise for goalkeeper David De Gea after the game following a man of the match performance.
“We had a good back four and David in behind them was unbelievable,” the Norwegian said.
“You are allowed to have a good goalkeeper.
“I’ve played with a few fantastic goalkeepers. We have a tradition of having them and he has grown and grown.
“He deserves that man of the match today.”
United remain sixth in the Premier League but are level on points with fifth-placed Arsenal.
Their next test is at home to Chris Hughton’s Brighton on Saturday (3pm).