He's not the first player to have a bad season after going to a major championship.
It's easy for strikers to kid themselves they contribute when they run their bullocks off, close down, challenge for every header and all that. With a man like Moyes you probably even get praise for it.
After 80odd minutes of running yourself into the ground closing a back four down on your own, when you need to get a yard on a defender to get in, or even just a solid connection on a shot it's less like to happen the more fatigue you suffer from. It's an undeniable fact that fatigue affects motor function. This is having an effect in a season where he's had less rest than half our side. If Moyes genuinely feels he's our main man he should tell him to play only in the box and focus on scoring.
The fact is your striker should always be your main goal threat unless you have an exceptional talent like Bale,Ronaldo etc. behind them. Moyes has never made our strikers our main goal threat. We've never had a player capable of excusing that either. Cahill, Felli and anybody else who's played no.10 are 10-12 goal players on average.
I'd prefer us to change our approach before we change the player.