"One of the things that was important was to maintain the base of last season is there, the squad is there," Nuno said at the 2018/19 Premier League Season Launch.
"It was about filling some gaps that we needed to fill, increase quality, bring experience and talent. All different things that we expect players to give to us."
Despite the step up, Nuno vowed to continue the attractive football his teams played on their way to winning the Championship.
"It's a challenge to prove ourselves that we deserve to be here, and we want to compete against these big teams, knowing their strengths, recognising their weaknesses, and playing in the same way we play," he said.
"We enjoy ourselves when we play football so we're going to keep doing it."