The Cork native (pictured above in green) joined up with the squad last night, ahead of today's opening training session in Johnstown House.

McCarthy is uncapped at Under-21 level, but was part of Stephen Kenny's home-based Under-21 squad that played the Ireland Amateur team in February 2019.

Jim Crawford will now have 23 players to choose from for next Tuesday's match in Pisa.

Bray Wanderers goalkeeper Brian Maher, St. Patrick's Athletic defender Luke McNally and Shamrock Rovers duo Brandon Kavanagh and Dean Williams will train with the squad this week in Ireland.

Republic of Ireland Under-21 Squad
Goalkeepers: Gavin Bazunu (Rochdale, on loan from Manchester City), Ed McGinty (Sligo Rovers)
Defenders: Nathan Collins (Stoke City), Darragh Leahy (Dundalk), Conor Masterson (Queens Park Rangers), Conor McCarthy (St. Mirren), Danny McNamara (St Johnstone, on loan from Millwall), Lee O’Connor (Tranmere Rovers, on loan from Celtic), Thomas O’Connor (Southampton), Dara O’Shea (West Bromwich Albion), Liam Scales (Shamrock Rovers)
Midfielders: Conor Coventry (West Ham United), Will Ferry (Southampton), Jason Knight (Derby County), Daniel Mandroiu (Bohemians), Connor Ronan (Grasshopper Zurich, on loan from Wolverhampton Wanderers), Will Smallbone (Southampton), Jack Taylor (Peterborough United)
Forwards: Jonathan Afolabi (Dundee, on loan from Celtic), Zach Elbouzedi (Lincoln City), Neil Farrugia (Shamrock Rovers), Joshua Kayode (Carlisle United, on loan from Rotherham United), Michael Obafemi (Southampton)

UEFA Under-21 European Championship Qualifier - Group 1
Italy v Republic of Ireland
Tuesday, October 13
Arena Garibaldi, Pisa
KO 16:30 (Irish Time)
#IRLU21