The Premier League transfer window is now closed, but clubs can still sign free agents at any point during the season.
Llorente, 34, has been without a club since having left Tottenham Hotspur at the end of June, and it remains to be seen where he will end up in the coming weeks.
Manchester United are potentially still on the lookout for attacking reinforcements after they agreed to let Romelu Lukaku leave the club and sign for Inter Milan in the summer.
And Liverpool FC legend Nicol feels that Manchester United would be wise to complete the signing of Llorente to add some more depth to their squad in the attacking department.
Speaking to ESPN FC, Nicol said: “I think this would not be the worst idea for Man United.
“Right now at centre-forward it’s a numbers game. They only have one and that’s Marcus Rashford.
“They don’t have another recognised centre-forward. Of course Llorente does give you another option.
“Man United under Solskjaer want to play attacking football, they want to keep it on the ground, they want to roll it around.
“But as I said, numbers-wise yes, and maybe even a change of direction now and again.
“I think this would be a good idea.”
Meanwhile, Manchester United are currently preparing to return to Premier League action on Saturday when they host Crystal Palace at Old Trafford.
The Red Devils were pegged back and held to a 1-1 draw by Wolverhampton Wanderers in their second Premier League game of the season on Monday night.
Manchester United signed Daniel James, Aaron Wan-Bissaka and Harry Maguire in the summer transfer window.
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