Jose Mourinho has mischievously highlighted the changing view of Jurgen Klopp after his Liverpool counterpart spent £75 million to sign Southampton’s Dutch defender Virgil van Dijk this week.

The Manchester United manager cheekily suggested on Friday that if he were a member of the media, he would ask Klopp about his comments, 18 months ago, when the German claimed he would not want to spend huge amounts of money even if it were available to him.

At that time, Klopp was responding to a summer in which United were on the verge of breaking the world record by paying £89 million for Paul Pogba - a figure “only” £14 million more than Liverpool spent this week to land van Dijk.

"You know, I think the one that speaks about it in a specific way has to be Jurgen," said Mourinho ahead of Southampton's trip to Old Trafford on Saturday.

"And if I was one of you I would ask him about his comments about one year ago.

"But I’m not speaking specifically about that case because in Liverpool they do what they want to do and I am nobody to comment on what they do.

"The reality is that if they think that the player is the right player for them and they really want the player they pay this amount or they don't have the player because that is the way the market is at that time."

Mischievous as Mourinho’s comments were, the United manager did concede that he has far pressing concerns closer to home with the form of his star striker Romelu Lukaku.

After opening his United career with 11 goals in 10 games, Lukaku has scored just four times in his last 19 but has, nevertheless, been required to play every minute of his club’s Premier League campaign due to the continued fitness struggles of fellow striker Zlatan Ibrahimovic.

Worse than that, Lukaku has been involved in errors in his own penalty area in recent weeks that have led to goals for Manchester City and Burnley - an indication, according to Mourinho, of possible fatigue.

- Grateful' -

But the United manager steadfastly refuses to criticise the Belgian striker, not least because he admits that he is unable to offer him any sort of rest in the foreseeable future.

Mourinho said: "First of all, people don't have to be grateful to Romelu, I have to be - not you, not the supporters, not the pundits - I have to be.

"The other day, I said 19 matches in the Premier League; now I say 20 matches in the Premier League, 90 minutes.

"I think for a striker, any player, that's absolutely incredible. But if you are a central defender, a holding midfield player, where you can control your energy, positional play, you can resist, survive.

"But for a striker to play 20 matches in the Premier League, 90 minutes, I have to be grateful for his personality and his character.

"Is he unlucky in our box in recent matches? He was in the picture, he was not a direct influence but he was in the picture in some of the last goals we conceded.

"Is that a consequence of a player that really needs a little rest, or is it just a consequence of the moment?

"The guy is fantastic for me and for the team and gives absolutely everything and I've no criticism. But no, I cannot rest him."

Mourinho tried to partner Lukaku and Ibrahimovic in the same starting line-up in Tuesday’s draw with Burnley, only to abandon the experiment at half-time with United trailing 2-0. And he admitted that with both stars struggling for form at present, he will not be able to pair them in the near future.

He said: "It can happen but I think to happen, they need both to be in their best moment and they are not."