REVEALED: Situation over Crystal Palace defender after reports of Portsmouth three-way battle with Bristol City and Wycombe Wanderers

But the Pompey boss admitted that could change between now and the summer transfer window.

The Blues were linked with a January swoop for the Irishman, with League One rivals Wycombe and Championship outfit Bristol City.

A deal never accelerated for the central defender, however, with Di’Shon Bernard instead recruited on loan from Manchester United in that area of the pitch.

The Republic of Ireland under-21 international is currently on loan with Belgian outfit RWD Molenbeek, and has a contract with Palace until the summer of 2023.

O’Brien has picked up plenty of game time as his side top the second division, operating as part of a back three.

Mousinho explained O’Brien is not a player he is currently aware of, but that doesn’t mean the Blues aren’t looking at the 21-year-old.

With sporting director Rich Hughes overseeing transfer policy and working with the recruitment department, it may well be further down the line before the Pompey boss becomes aware of players being targeted.

When asked if O’Brien is a player he knows about, Mousinho said: ‘Not at the moment.

‘I’ll have to look at that and follow it up when I’ve had a full rundown.

‘That’s the beauty of how we operate here at the moment.

‘I wouldn’t necessarily know every single player we’re in the market for and looking at.

‘But I will know by the time it gets filtered down to a list of players we’re interested in.

‘The players will all fit the profile of what we’ve been looking at over the past few weeks.’