The international manager will be casting his eye over Blues duo Ronan Curtis and Marcus Harness, as well as Brum midfielder Dan Crowley, ahead of his nation’s games against Switzerland and Bulgaria respectively next month.
Twice-capped Curtis has become a regular in the Eire set-up after being handed his debut against Northern Ireland last November.
The winger was named in the Republic of Ireland squad their 2020 European Championship qualifiers against Denmark and Gibraltar at the end of last season but was not utilised by McCarthy.
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Coventry-born Harness, meanwhile, has been on Ireland’s radar after impressing for Burton last season and declaring his desire to play for the Green Army.
The attacking midfielder moved to Pompey for a fee approaching £1m last month and was named in Kenny Jackett’s starting line-up for their League One season-opener against Shrewsbury.
McCarthy told the Football Association of Ireland website: ‘I’m going to the game (Portsmouth v Birmingham City), hoping to see three players involved in Ronan Curtis, Marcus Harness and Danny Crowley.
‘Marcus and Ronan both started for Pompey at Shrewsbury on Saturday and I’d like to see both of them.’
Defender Sean Raggett will be another Blues player hoping to catch the eye of McCarthy.
He missed the defeat at Shrewsbury with an elbow injury but is in contention to feature against Birmingham tonight.