Tino Livramento admits he needed to leave Chelsea for the good of his career.
The 18-year-old right-back has starred for Southampton since his £5m summer switch from the Blues.
He played his first competitive game at Stamford Bridge in the Saints' 3-1 defeat on Saturday, winning the penalty which James Ward-Prowse converted.
Livramento is now with England U21s ahead of Thursday's Euro 2023 qualifier in Slovenia and knows leaving his boyhood club was the right move.
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He said: "I feel like if I stayed there or did other things, then [playing Premier League football] wouldn't have happened as quick as it has now. I wouldn't say I have any regrets but it would have been nice [to have played for Chelsea].
"I had to think what was best for me. Being young, I've always wanted to just play first-team football as soon as possible.
"It was a hard decision for everyone involved. They agreed that it was best for me as well and they've always looked after me.
"I was at Chelsea for so long and grew up a fan and never played at Stamford Bridge in a competitive game. Saturday was a bit weird but I just enjoyed it that bit more playing against Chelsea and people I have trained against.
"I had a season ticket there for three years and my dad and brother still go - my brother is still a Chelsea fan.
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"You watch games there and coming through the academy I played a few youth games there on the pitch but nothing compares to a full packed-out Premier League game. It just felt a bit weird being on the other side.
"I'll never have a bad word to say about how they treated me growing up and developing me into the player I am today. It's probably the best academy in the world that anyone would want to go to and develop."
Livramento is among a talented group of English right-backs, with Trent Alexander-Arnold, Reece James, Kieran Trippier and Kyle Walker high-class competition for a spot in the senior side.
"They all compliment each other so well, they're all so good at what they do individually that it is so hard to pick one to start every game," Livramento added.
"They all have different qualities and it is inspiring looking up to them, especially someone like Reece who was at Chelsea and has done really well, played his games now, made that step up to the seniors and hasn't looked back."