Trump still hasn't been endorsed by six of his Republican rivals from the primaries:
Bush
Cruz
Fiorina
Graham
Kasich
Pataki
I'm not holding my breath on any of those folks endorsing him in the next two months. If they haven't done it by now, they probably won't.
The only one on the list above that may endorse him I think is Fiorina. But I highly doubt it. The rest? No chance.
And I'm actually not sure about Rubio. He only stated that he would vote for him. No real endorsement. Merely lukewarm. Very lukewarm.