Gordon, 16, has been with Chelsea for eight years and penned scholarship terms in recent months, with the ceremony being held at the club's stadium.
He told the club's website: "I’ve always imagined myself playing there, and I hope that day comes soon.
"Stepping out onto the pitch felt so different from watching a men’s match from the stands. It’s huge and feels like a stage, which I guess it is.
"Seeing the stands, walking down the tunnel, and getting a feel for the pitch was incredible. It’s everything I’ve wanted since joining as an Under-8. Chelsea means everything to me. I’ve been at the club since I was a young boy and have worked my way up.
"There have been tough moments and every footballer will say there are highs and lows. But it’s the highs, and the love of what you do, that push you further toward your dreams. That moment was one of my biggest highs, if not the biggest.
"One day, I know I’ll see my family and friends in the stands while I play a senior game. That moment will be special and I can’t wait for it."