Manchester United manager Ole Gunnar Solskjaer will not call Liverpool the greatest team in Premier League history until they have the trophies to prove it.
He still thinks that honour should be bestowed upon Alex Ferguson's treble-winning United side in 1999.
Solskjaer scored the dramatic late winner against Bayern Munich in the Champions League final that year to cap United's incredible campaign.
Jurgen Klopp's Liverpool are on course for a historic season of their own, holding a huge lead in the Premier League as they chase a first English league title since 1990.
They remain in the FA Cup and face Atletico Madrid in the last 16 next month as they try to defend their Champions League crown.
But Solskjaer believes Liverpool have to demonstrate the ability to keep winning year after year before they deserve to be ranked alongside United's best outfits.
"I would say our 1999 team was the best, but let's see when the season has finished," Solskjaer said.
"That showed we as a squad could cope with three tournaments. It was an amazing season, an amazing group, the personalities, the camaraderie.
"I'm sure Liverpool can win all three, so I'm not going to say yes or no, but let's see in May.
"You have to do it again and again and again and Sir Alex is the only manager who has won it three times.
"He had an exceptional way of motivating us and getting us ready, a way of just letting trophies be trophies, win them and move forward."
- 'The spirit is there' -
After so many years of watching United rule English football, it now appears to be Liverpool's turn again.
As United manager, Solskjaer would not want to admit to copying their Merseyside rivals, but he would love to create a side like Klopp's high-energy unit.
He believes he has taken the first steps to doing so, but more time is needed to complete the job.
"I can see a time when we have a team like Liverpool. The spirit is there, they are humble and they want to improve and that is a great starting point and foundation," he said.
"We know we need to sign a few players, but that's the club and we all understand that.
"We look at when Jurgen took over at Liverpool and he finished eighth in his first season so this is our first season together.
"Of course we want to build step by step, and layer by layer and in the end you can just send them out without having to wait until Saturday to do the last preparations because you know what they are able to do.
"If you look at Liverpool now with their front three, they all understand each other so they understand when he moves there and him there they drop and rotate. That's where we want to get to but that takes time."
The 1-1 draw between the sides at Old Trafford in October is the only Premier League game Liverpool have not won so far this season.
But Solskjaer is drawing confidence from how United acquitted themselves that day when they were at a low ebb as they travel to Anfield on Sunday.
"Last time we played them, we were really under pressure from everywhere," Solskjaer said.
"We didn't realise at the time but we were only a point off the bottom three.
"The players must have felt under so much pressure, but we didn't feel that, and I think they handled that game fantastically. And we are more confident now, definitely."
Ole Gunnar Solskjaer isn't ready to call Liverpool the Premier League's greatest ever team