Speaking ahead of Wednesday's match, Rosenior lamented an illness bug that took out Delap and Gittens and a couple of small injuries that have ruled out James, Palmer and Gusto.
He said: "We've been really unfortunate. Reece James took a knock on his hip and he's just not quite ready for this one. Unfortunately for Cole, he's obviously an outstanding player, he should be available for Saturday, but didn't quite make it for this one.
"Liam was ill three hours ago. Jamie Gittens fell down with illness. Malo, hopefully for Brentford. Yeah, we've gone through the wars the last couple of days, but at the same time I think we're good enough to be competitive and try to win this game."
Speaking about the threat Arsenal pose, he added: "They are very well organised in every aspect of the game. We have been tactically working on Arsenal since the minute I got into the building – including set-plays, which they are very good at. Arsenal are good at everything. I respect them and I think they will respect us."