Most certain to remain a starter (barring injury)/most likely to have the most minutes:
Eriksen
Lamela
Holtby
Lennon
Townsend
Eriksen looked like a star almost whenever he played. He had a goal/assist per 120 minutes last year. 30-35 combined this year might not be unrealistic if he stays healthy. He did miss a number of games with injury last year.
Lamela will get a run of games. If he plays like he did in preseason he'll remain a starter. But not producing and losing his place is much likelier for him than Eriksen. On the other hand, he has three goals in a total of about three games in preseason, and had 25 goals plus assists in an (incomplete?) year for Roma in Serie A. So a big year for him may not be a bad bet.
Holtby looks like a player Poch likes. He's also been one of our two or three best players in preseason. But he's likely to be played in a deep lying role (where he may be a starter, at least to begin the year), when I think he's better as an attacker. It's very hard to say with him. Anything from a huge year if he works his way into an attacking spot to being sold or loaned out in the next couple of weeks is entirely possible.
Lennon looks like he'll get considerable game time. He might just barely have the inside track to one of the three attacking spots at this point. But the odds of him holding off Soldado, Kane, Townsend and Holtby are probably less than 50/50.
Townsend looks like a regular sub at this point, which Lennon might well end up being as well. There's some sense in bringing on our two fastest players against tired defenders.
Ben Davies looks very much like the starter. Rumor has it that was part of the deal to get him to come here. I wouldn't call it cast in stone he stays the starter, since I think Rose is a more gifted athlete. But Rose has got to start playing more intelligently and more confidently. I doubt he'll dislodge Davies.
Bentaleb might be a very good buy as well. I'm not sure he's 20 yet and I think he's going to start for a long time, though perhaps not immediately. The combination of quick, smooth tackling and accurate passes over the top was very impressive against Schalke.