Gilmour joined Chelsea’s under-18s from Rangers back in 2017 for around £1.53m.
He then excelled at youth level and, when Frank Lampard was back at Stamford Bridge, was handed his senior debut.
Gilmour was especially impressive in the 2019/20 season, putting on some starring displays vs the likes of Liverpool and Everton.
However, following Lampard’s departure, Gilmour has struggled for regular football under Tuchel, despite the Blues’ midfield woes.
Now, Gilmour has left west London for Brighton on a permanent basis. And, speaking ahead of facing West Ham, the Chelsea boss has outlined why Gilmour was allowed to leave:
“He played some important matches for us and looked for a new challenge that did not go so well for him with Norwich.
“We expected more, he expected more so it was like, without pointing a finger, but it is difficult also for him and for us to not succeed, to not play at Norwich, to be relegated and then suddenly be a central midfielder for Chelsea and competing for top four and for every title.
“There’s a huge step in between so we were looking, the ideal solution would have been maybe that he goes again on loan as the concurrence is huge for us in central midfield and we felt like he is not the age where he can live again with five or six or seven matches during a whole season to fulfill his own potential so ideally, it would have been another loan.
“Billy did not want to go on loan, it was a no-go for him so in the end, we agreed to a sale.”