Marrone handled Nassib well, and if the past is any indication, I expect him to do the same with Manuel. Marrone brought in Greg Paulus for a year to start at QB before turning the reigns over to Nassib the next season. If I remember correctly, during the year that Nassib rode the pines, Marrone brought him in occaisionally at the end of a few games where SU had blown out an opponent. Unless Manuel blows away the QB competition this summer, Kolb or Jackson will probably start.
Based on what Marrone did in the past at SU, look for the older Kevin Kolb or TJax to start this season and Manuel to come in occaisionally at the end of games.