Having captained Argyle's Under-18 side, Oscar Halls progressed into the first-team environment ahead of the 2023/24 season. Having feature in the pre-season build-up, Oscar headed to Plymouth Parkway to start an educational loan spell with Argyle's city neighbours. 

Oscar made six appearances for the Pilgrims’ first team in 2022/23. They all came in the Greens' EFL Trophy run, as Halls made five starts and one substitute appearance.

In his second game, playing as a wing-back, Oscar scored his first senior goal, in a 3-1 win at Swindon Town.