I honestly have no problem with this. I have noticed that 4 and 5 star players expect to get some playing time. 14 receptions is NOT enough playing time and the Center leaving...I assume he wasn't used all year. This is why I refuse to use certain promises and if I do use them I sub them into certain formations or make sure they are on at least Special Teams. Also if you didn't make the No-RS 1st year and/or Solid Playing time 1st year then you are better off RS them so they don't leave. I have had some still transfer but this happens when you have 4 and 5 star players on a team thats loaded.
Also the Pro Draft declarations happens as well. Most don't make it but they still try. It also opens up the opportunity for others to play. I had 5 players declare for the draft 2 Juniors and 3 Sophs in my Dynasty. Sucks but it happens. Luckily I had some solid recruits and was able to go with out them.