The Anglo-Nigerian defender joined the English Championship side on transfer deadline day and joins Michael Hector and Aina who was called up by the Nigerian national team for their double-header against Cameroon.
And the youngster who can play for Nigeria, Canada or England at senior level spent the second half of last season at English Premier League newcomers Brighton and Hove Albion making nine appearances.
"I spoke to both of them before coming here and it's good to have some familiar faces here already," Tomori told club website.
"It was a factor in me coming here. To be fair, Ola has been on at me to come up here ever since he made the move!
"I'm pleased to be here now. Obviously, I was away with England when I signed, so the excitement has been building for a few days and I'm looking forward to getting started.”
And Tomori believes the experience he gained at the Seagulls will help him overcome the rigours of the English second tier.
"Hopefully it can be a similar experience here in terms of pushing for promotion, but hopefully I can get a bit more playing time,” he continued
"Experiencing the Championship last season makes me feel a little bit more confident in terms of what to expect this time around.
“It was unknown to me when I arrived at Brighton but, after watching it closely and playing in it, it has helped me a lot and I'm looking forward to playing in it again."