According to a report by PWInsider, the reason that Zelina Vega has not been on WWE TV is due to an in-ring injury that required surgery.
It is being said the belief is that she will likely be out of action for 6-8 weeks, which means her return would be around Summerslam.
The report also notes that there has been talk about Vega receiving a push upon her return, as sources noted her willingness to do what is requested, as her hard work has been noticed behind the scenes.