Fans think they’ve worked out the real reason.

Fans think they’ve worked out why Celtic fans booed Jack Grealish during their 4-3 win over Manchester City.

Celtic won a competitive pre-season friendly in North Carolina, with January signing Nicolas-Gerrit Kuhn scoring twice.

The reigning Scottish champions were up against a depleted City side, but one which still contained the likes of Grealish, Erling Haaland, Ederson and Stefan Ortega.

Grealish wasn’t selected in the final 26-man England squad for Euro 2024, meaning he has been able to take part in a full pre-season with Pep Guardiola’s side.

But the 28-year-old was roundly booed by Celtic supporters in North Carolina – and fans at first weren’t entirely sure why.

Some, though, have come to the conclusion that it is Grealish’s international allegiance that sparked the boos.

He represented Republic of Ireland at youth levels before committing to England at senior level. Grealish was born in Birmingham, but is of Irish descent through his maternal grandmother, paternal grandmother and paternal grandfather.

Traditionally, many Celtic supporters were of Irish descent and Roman Catholic, with the club having a strong Catholic heritage.

Fans, therefore, have hypothesised that Grealish’s decision not to play for the Irish national team may have been the main factor behind the reaction to him in the United States.

According to the Daily Mail, meanwhile, the 28-year-old is fully focused on putting his England disappointment behind him next season.

It is claimed that Grealish has put in place a series of measures that he hopes will help improve his form at City after starting 10 of their 38 Premier League fixtures last season.

That was a much lower amount than the previous campaign, where he played a key role in City’s success in winning the Premier League title and was directly involved in 12 goals, with five of those being goals.