Depends on how you are looking at it. If Pep specifically requested both players the only way they are not starters is if they suck or get injured. From what I've seen. Neither one of those 2 suck, I think they'd become the starters sooner than later.
As for Denayer, I think hoping he becomes a starter here is mostly our hope, at Galatasary he is mostly deployed as a Right back. As for our original 3, we have an Injury prone Captain and 2 guys who interchange between starting, most dont thinks either has laid claim to being an undisputed starter. Both have shown some good qualities and some bad. Neither is half the passer these 2 are. And Pep wants ( I think) intense possession potential.
More likely than not, we sell one of those 3 and add these 2. One of these 2 become a starter from the beginning, and the other if Kompany's hammy acts up again. Whoever stays of Màngala/Ota becomes a backup or spot defender.
Denayer in my mind really doesn't factor in a role at CB. At least not this year. Best case scenario, he owns the RB spot for now àns becomes the defacto backup to the incoming duo in 2 years.
Unless that is, he can beat