Lascelles is in his second season as Magpies skipper.
He said: "I think I'm a big character in the dressing room, though, so I'm more comfortable with it.
"It would have been more difficult had I become the captain immediately after I signed, but I've been at Newcastle for a few years now and that's been a huge help.
"I know everyone and there's a level of respect there already.
"It took me a little while to understand how to get my message across to some of the squad. Rafa has sat me down on a few occasions and explained I can't communicate the same way with every player."