I dont think either should go - Carroll has had a few good games, thats all, and needs 99 chances to score. Had he stayed with Toon, I think he would have gone, and he certainly could be a good player in the future - not now. Holt, I am not sure about. Yes, he has scored goals but its one thing doing it against the likes of Bolton, Wolves, Blackburn and Liverpool and another against France, Germany etc...
As Roy is liikely to take just 4 strikers (Walcott would be a 5th option but counts as a mid), it would need to be Rooney and Crouch on form - then Bent if fit is a must. Sturridge and Welbeck are better than Carroll on form, and then you have Defoe - poor season but left on bench for most and we know how dangerous he can be.