Oxford made his debut for the Hammers during the first leg of their Europa League first qualifying round against FC Lusitans on Thursday evening.
The 16-year-old defender played well against the Andorran side and was impressive during the 3-0 win at the Boleyn Ground.
The England Under-18 international captain normally plays as a centre-back, but on Thursday he featured as a midfielder.
Oxford became the youngster ever player to play for West Ham, breaking Billy Williams' 93-year record in the process.
Westley was impressed with the performance of the teenager on his debut and was full of praise for him after the match.
“He has done well and it gets that out of the way,” Westley told West Ham’s official website. “It was the ideal night to play him and to play him in midfield to quicken his feet up.
“Then, when he stepped back towards the end, he was in control of the game and getting the ball and punching it to the wide men.
“He looks a prospect and now he knows he still has a lot to do, a lot to learn and a lot to work for. That was the other reason to put him in. He’s not the finished article, but we’ve got a real prospect on our hands.”
It was a memorable debut performance from Oxford, who showed that he can be effective in midfield.
The youngster looked calm and confident when he had the ball at his feet, and also tried an ambitious effort on goal from 30 yards.