As noted, WWE released Ricardo Rodriguez last week. His contract was set to renew the night after SummerSlam.
Ricardo had been frustrated that he wasn’t really being used as a wrestler in any significant way after Alberto Del Rio turned on him. Ricardo has reportedly been injured recently also.
The original person WWE wanted to use as Del Rio’s “personal ring announcer” told people that he wasn’t interested in doing ring announcing, which led to Ricardo getting a tryout around SummerSlam 2010.