Surely, SPP is the sole defensive forward. DBJ was a stop gap and that gap has now been stopped.
I don’t think SPP should be a defensive forward at all. Once fit, he should spend sometime in the midfield rotations again as we have other forward options and play more of an enforcer role when he is up forward. We’re wasting his other abilities if we just want him to play defensively and follow his opponent around.
DBJ is more limited as a player and doesn’t have that ability to pinch hit in the middle. That’s why I’d have him play that defensive role while the other forwards have an attacking mindset and rotate up and down the ground.