I'm going to come across like an old man here but there's no motivation for them to be the best version of themselves.
What's DCL wage, let's say 75k per week. He's doing what most people do, turning up doing a job of sorts and clocking off.
If there was a way to motivate the modern footballer then it would likely be via their pockets although most are already made for life by mid 20s as middle of the road EPL striker.
He's not being helped by morose tactics to be fair. Lumping a hopeful Pickford/Tarky front to back and abject crosses from wide can't help his cause.
I'm a big fan/supporter, but sometimes you just have to be honest and accept He's maybe not all that ! (In a better side he'd be a 15 a season player easy)