While I agree with the sentiments of @OG37on this misuse of the term ‘doppleganger’, this is a grand little game:
Bryan O’Mara (Tipp 2020s) and Brian O’Meara (Tipp 2000s)
Joe Caesar (Holycross/ Ballycahill, Tipp underage 2020s) and Joe Caesar (Killenaule and a few Tipp appearances in 2000s).
Steven O’Brien (Cork footballer 1980s/90s), Stephen O’Brien (Kerry Footballer, 2010s/20s) and Steven O’Brien (Tipperary footballer and sometime hurler, 2010s/20s).
Jesus, influencer from a couple of thousand years ago, ended up on the cross
Jesus, Arsenal forward. Rarely influences games or gets on the end of a cross.
David Reidy (current Limerick hurler) & David Reidy (current Clare hurler)
Shane Kingston (current Cork forward) & Shane Kingston (current Cork back)
Sean Finn (the greatest corner-back to ever live) & Sean Finn (Irish revolutionary, namesake of Rathkeale GAA)
Stephen Kelly (Limerick footballer) & Stephen Kelly (formerly of Ireland, Tottenham & Fulham, current RTE pundit)
James Ryan (former Limerick dual player), James Ryan (Limerick team doctor), James Ryan (Irish rugby player), James Ryan (former Minister for Health)
Damien Delaney - Leix football and Cork Minor football/Crystal Palace
Barry Brennan - Leix football and Galway football
Paul Murphy - Kilkenny hurling and Kerry football
David Fitzgerald - Clare hurling and Clare hurling
Paul Walsh - Cork footballer and Liverpool footballer
Brian O’Driscoll - Cork footballer and Ireland rugby player
Tommy Walsh - Cork footballer and six generations of Kilkenny hurlers, among others