The Scotland Under-21 international is still only 18 but has made remarkable progress since moving to Stamford Bridge in the summer of 2017.
Gilmour left Rangers to move south and many questioned the youngster's decision. But the midfielder has enjoyed a significant breakthrough this season, with two starts in the League Cup, his Premier League debut in August and a substitute's appearance in the FA Cup tie against Hull last month.
Such is his progress that Chelsea manager Lampard has moved him out of the development squad and into the first-team dressing-room alongside star names such as Willian, N'Golo Kanta and Tammy Abraham.
"It’s a massive moment for me and I’m really happy," Gilmour said of his promotion.
"I went with the squad to Leicester and even though I wasn’t involved, the gaffer pulled me afterwards to tell me that after the winter break I’d be with the first-team permanently."
In an interview with the Chelsea website Gilmour spoke of the boost he got from knowing Lampard had such faith in him.
"It’s a dream come true for me," said the teenager. "It’s the first big step I think, moving into the first team dressing room at a club like Chelsea. It’s massive for me.
"Knowing that the manager has such faith in you is massive, it gives me so much confidence when I step onto the field. It’s really good knowing that he trusts in you and likes the way you play, and I think that’s the same for everyone here.
"Age isn’t really an issue here. The gaffer has shown that if you work hard and perform well, then you will get opportunities. Hopefully I can keep pushing on and work hard every day in training."