He's had a bad season and a lot of that has been due to injuries, but he's almost lost his identity these last 12 months. In the World Cup he was used as one of a 3 man midfield in the 352 but never looked quite comfortable in it. He did his job but it wasn't a role that he was suited to. When playing in a midfield 3 for England's new 433 he has still looked more of a functional part, shackling himself to the system but not using his best attributes.
Dele's skillset is best suited when being given the freedom to float into those half spaces in the attacking third and making the clever moves off of Kane to find himself in front of goal. This brings me on to us, where we either play a 442/4231 with Dele playing off of Kane or a diamond with him at the tip. Now the diamond has worked well enough this year, but I wouldn't be suprised to see us switch things up if we get the targets we are after and with the wingers and midfielders we are being linked to, it looks like a 433 could be the shape.
If so, I think Dele may find himself struggling to get in the starting lineup next season.