Man Utd head coach Michael Carrick has been cautioned by Wayne Rooney that he is unlikely to be given much time to make his mark in the Old Trafford dugout.

The Red Devils brought in five new players during the summer transfer window, with Andrey Santos (£48m, Chelsea), Karl Darlow (free, Leeds United), Youri Tielemans (£35m, Aston Villa), Tynan Thompson (£8m, Tottenham) and Carlos Baleba (£65m, Brighton) all joining the club.

Realistically, Tielemans, Baleba and Santos are the only three who look capable of making a notable impact for Man Utd this season, with Darlow arriving as a back-up goalkeeper and Thompson viewed as a promising young talent.

Man Utd began the campaign in disastrous fashion on the opening weekend, losing 2-0 to newly-promoted Hull City at the MKM Stadium.

Since then, Man Utd have beaten Ipswich Town 5-2 and were held to a 2-2 draw by Everton in the Premier League, making for an inconsistent start to the new season.

Offering a frank assessment of what it is like to manage Man Utd, Rooney warned Carrick that he will not be afforded much time before questions over his position begin to surface.

Speaking on the Stick to United podcast, Rooney said: “If you’re manager of Manchester United you know the pressure which comes with the job and the time now you’re not getting much time in the job.

“You have to push as hard as you can even harder to get players in because you know you don’t want to be sitting here in six months, 12 months’ time, saying ‘You know what? I should have’.

“Do we want to win the Champions League? Of course we do. But in terms of this process we’re going through to try and get back to that, we’re going to have to accept we’re not quite at that level yet. Arsenal have been through this process over the last five years with [Mikel] Arteta and you’ve seen the progress each year.”

Carrick has publicly appeared satisfied with Man Utd’s summer business, despite the club not signing any new defenders, and Rooney believes the former midfielder is simply putting a brave face on the situation.

Rooney added: “I know Michael’s come out and said he’s happy with the players they’ve got in. I don’t think any manager’s happy.

“He’s going to have to come out and say the right things. Of course… every manager does that. But he hasn’t got time to wait for next year. He can’t sit there and go ‘Well, you know what? I’ll wait till next year,’ then I’ll have my defence sorted. You’re getting more and more American owners who want success straight away.”

On the club’s failure to bring in players who can help Bruno Fernandes lift Man Utd further up the table, Rooney continued: “There is nothing in there which is saying to me now these players are going to take Man United to the next level. I love Bruno. I think he’s brilliant.

“He must be thinking ‘Please bring me some help. I’m doing everything I can. Help me’. And I don’t think the club have done that with the signings. You’re not sitting there saying you’ve got these four players, we should be winning the Premier League.”