It may be a normal pet parent that actually needs service. Many people who move hold onto an out of area number for a variety of reasons (i.e. sentimental, identity, friends& family in that area, etc).
Next, look on this person's rover profile for the Rover number assigned to them. It should be listed as (858) xxx-xxxx. You can safely call and text that number. It will mask your phone number and the call will automatically get relayed/forwarded to his number provided on the profile. You can discuss all the details, set up a meet & greet. BTW, on their screen, they can see, dial, call, and text the (858 )xxx-xxxx rover number assigned to them to contact you, so you do not have to give out personal information if not comfortable doing so. Afterwards, when you're ready to book, if he's having problems booking online, you can refer him to support at [Edit: Rover’s contact options have changed. Visit the Rover Help Center at https://support.rover.com/ to find the phone number, help articles, or chat with the team]. They can also take his payment info and process over the phone.