NO WAY!!! TMZ.com
It's safe to say John Cena didn't give any of his "Peacemaker" costars a heads up about his hair transplant ... 'cause TMZ broke the news to Frank Grillo this week -- and he couldn't have been more floored by the reveal.
We chopped it up with Rick Flag Sr. out at LAX ... and while we chatted a bit about the new season of the hit Max show dropping later this year (skip the first 30 seconds of the clip if you haven't watched S1 yet), the topic of the WWE Superstar's recent life-changing decision made Grillo stop in his tracks.