It is being reported by the Wrestling Observer that Sol Ruca is indeed out with an ACL injury.
Just the other day, the NXT Anonymous Twitter account caught Ruca getting attacked at the WWE Performance Center. This was a way of writing her off as they have done in the past with Nikkita Lyons and Wendy Choo.
The last Ruca wrestled was at the April 14 live event when she teamed with Dani Palmer against Jakara Jackson & Lash Legend. The last on screen match was the April 11 episode of NXT when she faced Tiffany Stratton.
There is no word on how long Ruca will be out at this time.