In their prime, Baines and Jagielka would have got regular first team football at CL clubs, Mirallas probably not. Baines and Jags are now nearing the end of their careers, so, sooner or later, probably sooner for Jags, they'll need replacing, i don't think anyone really doubts that. At that point they'll probably be given the same option as was presumably given to Barry when Schneiderlin signed, basically saying we're happy for you to stick around, but you won't be first choice any more so may well be on the bench more than you are in the first eleven.
That'll likely happen with Jags next season, possibly with Baines as well, though that's more likely to happen the season after.
As for Mirallas ... useful player to have in the squad, but, as for large parts of this season, he's not been guaranteed a starting place any more so the ball's in his court.
Are you not familiar with Zat's view on life ?