Sidebottom still injured - well more recovering tbh
Onions plays with Hamison up in Durham, his bowling average is low 30s, and he has a fair amount of first class experience at 26 years of age. Not sure you'd get the right playing conidtions darn sarf in landan for Onions, but I guess against the Windies he may be worth a try. Can generate a fair bit of pace too - mid to high 80s when hes in midflow, but dont see it too often tbh
Bresnan...he has played for England before (in ODIs) but a time to forget, and something Bresnan will have erased from his memory. 3 years ago against Sri Lanka when he was 21, he was smashed to every corner of the ground by the top order - the one match I remember well of his was at his home ground; Headingly, he bowled 2 overs all game and went for 29 - Jayasuriya mustve thought he was in the nets...
His average is around low 30s too, and is medium fast-ish, almost two similar bowlers.
You'd rather give them experience against the Windies then have them in the Ashes squad...I think the batters should be priority here - really be looking to get some runs and some 400+ innings.