Cullen captained the Republic of Ireland Under-21s and played alongside fellow Hammers man Rice in the team.
Josh Cullen and Declan Rice have enjoyed similar trajectories to the upper echelons of football, both being born in London, coming through West Ham United's academy, and qualifying for the Republic of Ireland through paternal grandparents
The two Hammers were scouted by Mark O’Toole and were teammates for Ireland's Under-21s, with Rice going on to make three senior appearances last year, but then the two players' paths split as the latter went on to declare for England.
Both players are in line for their senior international debuts with their respective nations, with Rice potentially featuring for England's Euro 2020 qualifier against the Czech Republic at Wembley on Friday and Cullen in line to start for Ireland in Gibraltar the following day.
Speaking about his friendship with Rice, Cullen - on loan at Charlton Athletic from West Ham - insisted that he never sought to try and convince his teammate of a decision one way or another, stressing that "everyone is different" and that the two wished each other well in terms of their respective international bows.
“Dec had that in his mind that he wasn't sure what he wanted to do," Cullen, the former Under-21s captain (Transfermarkt) is quoted by the Irish Mirror as saying. "He's made the decision and now we wish him all the best. Hopefully he has a successful career. But I just left him be.
“He's a friend of mine so we both wished ourselves well and we'll both move on now. Only he could have made that decision.... it’s a surprise that someone so young is doing so well but he's definitely got the talent and full credit to him for delivering when he got his chance.”
Cullen, 22, was not initially named in Mick McCarthy’s initial 38-man squad but he impressed the Ireland boss in Charlton’s recent win over Burton Albion and was named into the final 23-man squad after Alan Browne was ruled out (Irish Mirror).