Nathan Riggs (Martin Henderson) might cause a lot of trouble in Grey Sloan Memorial Hospital when "Grey's Anatomy" returns to ABC for season 13 this fall.

In season 12, Maggie (Kelly McCreary) realized that she is already falling for the cardiothoracic surgeon and told her sister Meredith (Ellen Pompeo) about it. But viewers of the show were shocked when they saw Mer getting physically intimate with Riggs at the parking lot during the penultimate episode of the season.

Even if Mer told Riggs that she has no intentions of having a relationship with him, Henderson believes that his character could be involved in a possible romance with her in season 13.

"I think that's always really powerful between a couple," the actor told TVLine in an interview. He added that the connection between Riggs and Mer "may be fertile ground for them to actually have a relationship with some meaning."

He also said that the possible romantic relationship between the two doctors will be beneficial for Derek Shepherd's (Patrick Dempsey) widow.

"Nathan is irreverent and kind of calls Meredith on her s—, and that might be really good for her, because he doesn't take [things] all that seriously," he said.

But the actor also stated that it would be interesting to find out who among Riggs and Mer would first confess about having feelings for the other in season 12.

Starting a relationship with Riggs could cause problems between Mer and Maggie, since the latter also thought that Riggs has feelings for her. It could also hurt the fans who are rooting for Mer's potential romantic connection with her best friend Alex (Justin Chambers), who is already considering to break things off with his relationship with long-time girlfriend Jo (Camilla Luddington).

"Grey's Anatomy" season 13 will return to ABC's Thursday timeslot this fall.