My first year too, seems to me defenders wise probably better to sub in someone even if their average but in a team you think can keep a clean sheet that week (say Everton v Watford and the latter are on a poor run), where as strikers aren't such a big issue, as it's common to score but not win. That said I have subbed Benteke out for...Callum Wilson, my boy is gonna score multiple against Villa where as Stoke gonna shut Tekkers out, you readz it ere first.
Still gonna be bottom of group C knowing me lol.