Rachel McAdams Talks 'Southpaw' Jake Gyllenhaal Transformation Amid Dating Rumors

Rachel McAdam's might be rumored to be dating her True Detective co-star Taylor Kitsch, but it is her Southpaw co-star, Jake Gyllenhaal that she can't seem to stop gushing about. While Rachel and Jake are both on the road doing their press tour for the upcoming boxing flick, the former Mean Girls star couldn't help but admire her cast mates commitment to the sport's flick. The two might have stirred up dating rumors in the past, when they were spotted out and about on a few dinner dates, but while they assured the press that nothing was going on at the time, one could easily get mixed signals especially after the kind words that McAdams had to say about Jake earlier this week.

According to Radar Online, Gyllenhaal changed his appearance dramatically for the picture by adding 15 pounds of muscle to his toned physique, which Rachel said was drastically different from when she saw him during his training.

"I really wasn't surprised just based on what kind of an actor he is and the work we've seen from him before," the starlet explained. "But when Jake was first starting to box, and I went to met him at the gym, he has a big bushy beard and a ponytail."

The starlet addressed Gyllenhaal's transformation in an new interview with Yahoo Style, saying that once they both got to set for the first day of shooting, he not only appeared physically different, but that he was emotionally different as he had seriously tapping into his character.

"When I first showed up on set on day one, he was in the middle of shooting that first fight in the stadium," The Notebook star revealed. "I was just so unprepared and it was just amazing to get closer and closer to that ring and see him emerge and what he had done — not just the physical transformation but even his emotional shift was so palpable. He had become this person on a cellular level. So really extraordinary. Very awe-inspiring."