This follows on from his visit to Norwich last week to eye-up Wes Hoolahan & Anthony Pilkington in their impressive defeat of Arsenal at Carrow Road.
The Stoke v Sunderland game could feature up to seven potential members of the squad for next month's friendly with Greece at the Aviva Stadium.
Potters boss Tony Pulis will likely start with Marc Wilson and Jonathan Walters, who both impressed in the comfortable win over the Faroes, while Glenn Whelan will be involved if he shakes off his hamstring problem.
John O'Shea and McClean are regular starters for the Black Cats, while midfielder David Meyler, who has broken into Trapattoni's plans in recent months, might be brought off the bench at some stage.
Ireland's first-choice goalkeeper Keiren Westwood may need Simon Mignolet to suffer some kind of misfortune if he is to get the chance to impress O'Neill and nail-down a a regular Sunderland starting birth.
It will be interesting when the Ireland squad is announced for the Greece friendly next wednesday, if Trapattoni's sudden ability to watch players on a regular club basis will have any bearing on his squad selection.
.
