The Englishman was announced as Rafa Benitez's replacement on Wednesday.
Speaking after a 4-0 loss to Wolves in China, Lascelles said: "We're all looking forward to it. We've been waiting for him to come in. There's been speculation and now it's confirmed, we're pleased and we're looking forward to it.
“He's a very well-known manager who's done well in the Premier League and the Championship.
“We've been working hard with Ben [Dawson] and Neil [Redfearn] – they've done a great job and the rest of the staff have helped us out as well.
“Now the manager has come in, we're really looking forward to it."