Oatway believes that Poyet will act decisively and quickly in the transfer market ahead of his first full campaign in charge at the Stadium of Light.
Poyet is a contender for Premier League manager of the year after safeguarding Sunderland's top-flight status following a five-game unbeaten run that included wins over Chelsea, Cardiff City, Manchester United and West Brom.
And Oatway insists that Poyet is already busy planning for next term.
"Pre-season is a big time for most managers but especially for Gus," Oatway told reporters ahead of Sunday's final game of the season against Swansea City.
"I imagine he will want to complete any business he can as quickly as possible.
"Gus likes to get what he can, the majority of his team, in place so he can coach them in pre-season.
"He likes to have that five or six weeks to work with them before the season starts."
With Premier League safety assured, Oatway has hinted that Poyet may tinker with his side against Swansea to avoid injuries.
He added: "It's coming towards the end of the season and everyone's got half a dozen niggles in their squad.
"The players have given everything for us and the last thing we want is injuries going into the summer.
"We'll assess things and wait before deciding the team."
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