Credit: Twitter

There have been plenty of fantastic guest stars throughout Grey’s Anatomy’s nine seasons, including a number of musicians, but we never thought we’d see teen heartthrob Justin Bieber at Grey Sloan Memorial.

But alas, it happened. Star Jason Winston George (aka Bailey's hot hubby, Dr. Ben Warren) tweeted a pic with the Biebs on set today, posing with a serious look on his face as Justin throws his hood up.

However, with a closer look, it isn’t what it seems. Don’t worry, Grey’s fans — the pop sensation isn’t really invading the hospital; it’s just a cardboard cutout.

“Seriously? Somehow there is a 'life-size' Bieber cutout at #greysanatomy,” Jason tweeted earlier today. “And by life-size I mean enlarged to 130%.”

We were thinking that Justin looked a little tall there. Hopefully more cast members posed with him and will be tweeting their own selfies shortly!

Would you freak out if Justin actually guest-starred on our fav show? Sound off below.

Catch the next new episode of Grey’s Anatomy on Thursday, May 2, 2013, at 9 p.m. ET/PT on ABC.

Alyse Whitney is an editor at Wetpaint Entertainment. Follow her on Twitter @AlyseWhitney.