References with unknown phone number

<p>Hey everyone, </p>

<p>I'm applying to this company that requested phone numbers with no option of providing an e-mail address; however, at the company I was at last summer, I communicated with my mentors and other members of my team strictly in person or by e-mail. I never got their phone numbers because there was no need for it. </p>

<p>Should I contact them? I feel like it would be an awkward e-mail/conversation. I'm not sure if my previous employer/team expects me to return.(they mentioned what I would work on next summer but did not explicitly say "You have a job next summer" ... sort of non-committal, but then again, they didn't give me a hard-cover copy of my cover letter until less than 3 weeks before my start date)</p>