The academy product shares a strong bond with the club, having been here for eleven years and Sinclair is thoroughly enjoying his journey at Southampton.
The youngster is refusing to rest on his laurels though as he targets all-round improvement – both physically and in footballing terms.
“I’m delighted to sign,” the 19-year-old enthused when speaking to the club’s official YouTube channel
. “I’ve been here since I was eight and hopefully I can carry on progressing as I was last season and hopefully I can get in the manager’s plans for this season.
“I know everyone, know all the staff. It’s good to be here and hopefully, when I get started, I’ll kick on here and sign another new deal.
“I think need to improve everything. I need to get bigger, need to get faster and I need to be more clinical in front of goal. Martin’s a great coach and I need to produce whenever I’m with him.”
Sinclair netted five times for the Development Squad last season – a total he’s looking to build on in an attempt to impress new manager Ronald Koeman.
The forward was included in the Dutchman’s first-ever training session at Southampton on Monday and it’s made Jake eager to remain under consideration for senior plans.
He continued: “I always demand more from myself, so hopefully next year when the season starts I can get another couple of goals when I start.
“I think it (training) went well; we started quite light. As the weeks progress I can imagine training will get a lot harder.
“I do want to stay here and fingers crossed I can produce in training so hopefully I can get into his (Koeman’s) plans.”