And the Pompey boss has given an insight into the untold story behind the marquee summer signing’s slow start to life at Fratton Park.
Expectations were high when the Northern Ireland international’s signature was captured, after his exit from Championship Cardiff.
Whyte’s form has yet to spark, however, but there was a tantalising glimpse of what could be to come, after his second-half introduction at the DW Stadium.
The 27-year-old produced a number of classy touches and driving runs, with one near-post effort saved by Latics keeper Sam Tickle.
Mousinho gave an honest assessment of his former Oxford team-mate, while looking forward to what’s on the horizon.
He said: ‘I spoke to Gavin and said “that’s better, that’s more like it and that’s the sharpness we need”.
‘That’s the sharpness I know Gavin can produce having played with him and watched him over a number of years.
‘We’re not hiding behind anything, we feel we haven’t quite seen that yet.
‘It’s a really good place to be in some ways, because we know there’s more to come - but we also have to get more out of him.
‘It was a really good step in the right direction for Gav and he looked really sharp.
‘The only thing needed from him was a goal.’
Mousinho highlighted the factors Pompey fans may not have seen behind Whyte’s form to date, after a summer in which he became father and searched for a new club after his Cardiff release.
That led to a lot of movement between Wales, Northern Ireland and England, along with the new demands of parenthood on top of his Fratton move.
Mousinho added: ‘There’s always context.
‘As fans you see what goes on when they are on the pitch, but there’s a huge amount which goes on for these guys.
‘With Gavin, he’s come over after moving from Cardiff back to Belfast in the summer because he didn’t know what club he was going to sign for.
‘He had a young child in August and that’s a tremendous amount of upheaval, so sometimes it takes a bit of time to settle.
‘Obviously, the quicker it happens the better but all players are individuals and we have to treat them as such.
‘I know with two children myself it can be a tough one as a professional footballer.
‘Unfortunately, you have to leave your wife to do the nightshifts and all that stuff plays a part in it. It’s up to use to be aware of these things.’