Celtic’s transfer business will be the sole focus of the fans this summer. Well, that and the four players going to Euro 2024. As the build-up to the big tournament in Germany continues, the Celtic fans will be eager to see how Callum McGregor, Greg Taylor, Anthony Ralston and James Forrest fare against the best players Europe has to offer. However, transfer business is always on the Celtic fans’ minds and they will be keen to see how Brendan Rodgers plans to spend the Champions League millions he is set to inherit for winning the league. And as additions to the first-team are important, so ar…