How Does Leo Carlsson Change Flyers' Lineup?

Throughout the entire rebuild process, the Philadelphia Flyers have chased after a No. 1 center, and after signing Leo Carlsson to a blockbuster offer sheet on Friday, they may very well have found one.

Assuming the Flyers really do get Carlsson, and the Anaheim Ducks are unable to match, what actually changes in Philadelphia? What does the lineup look like now?