John Mousinho: Why we must hold back Saturday goal hero from Portsmouth first-team - for now

Yet the Australian under-23 international is edging towards being let off the leash as the Blues seek to maximise his attacking potential.

Yengi marked his Pompey debut by grabbing a stoppage-time leveller against Bristol Rovers on Saturday.

He had only been on the pitch since the 83rd minute, representing Mousinho’s fourth and final substitution of the 1-1 draw.

Coming into pre-season a week later than his new team-mates, followed by an ankle problem, has meant the Blues are cautiously managing his first-team minutes.

It’s through necessity rather than any indictment of Yengi’s ability, but with a Carabao Cup trip to Forest Green Rovers on Tuesday night (7.45pm), more on-pitch time could be in the offing.

Mousinho told The News: ‘Kas is off the mark now – and off the mark early.

‘It was a really good goal, probably the best ball we put in all game, and he rose at the back post. It happened in slow motion for me.

‘We have seen time and time again that pressure which builds when waiting for that first goal, but thankfully he now has his.

‘He did brilliantly on Saturday coming on for seven minutes and scoring a goal. Kas is really popular around the place and it’s a big transition coming over from Australia to this country.

‘There are also the demands of what we’re asking him to do, that’s a tough thing, and one of the reasons why we are introducing him to the fold relatively slowly.

‘He’s such a strong, powerful, physical specimen as well, we don’t want him to break down, although he just wants to go and go and go and go.

‘Sometimes with Kas we have to hold him back, just making sure he knows that he’s building into 10 minutes. He can do far more than that, but we’re just building into that.

‘He is so quick and dynamic, you really have to make sure those players are ready for full league action in case they pick up an injury.’

Yengi, Christian Saydee and Abu Kamara all made positive contributions after used in the second half against Rovers.

Saydee was man-of-the-match following his half-time introduction, while Kamara was involved in the build-up to Yengi’s goal, holding up the ball before laying it off to Joe Rafferty.

And Mousinho has challenged all those who didn’t make Saturday’s starting XI to stake their claim when handed the opportunity – either from the bench or in cup competitions.

He added: ‘There’ really fierce competition for places in the squad and starting line-up.

‘The big message I’ve tried to convey to the players when naming the team this week is everyone’s going to have an impact.

‘I may feel like the worst thing in the world because they’re not in the starting line-up – and that’s how I want it to feel in a certain way.

‘We need them to prove to us we made the wrong decision.’