I think the other reason why this line-up was so reserve heavy is because of Saturday night's game. If you are trying to get a team ready then you also want them on the right routine. Saturday should be the last run out for the starters. My guess is he wants to see his first XI go 75' and play his system. It was tough to do that with two mid-week games back to back. With the possible exception of the Open Cup window, there's no point in the season where the team would play four games in two weeks.