The midseason finale of "Grey's Anatomy" ended with Meredith and Owen talking about his beef with Nathan Riggs, and it looks the issue is connected to Owen's sister.

In light of this discovery, any interaction Meredith will have with Nathan is going to be fraught with more tension.

When Martin Henderson joined the cast of "Grey's Anatomy", it was widely speculated that he would fill the void left behind by Patrick Dempsey's departure. There were also talks of him playing Meredith's romantic interest. But from the looks of Nathan's interactions with Meredith, a romance might not be on the cards for them in the near future.

So what can we expect from Nathan and Meredith in the second half of the season? More fighting, says Henderson

"There's definitely some stuff where Meredith and Riggs butt heads," Henderson told Entertainment Weekly. "He starts pushing back and starts getting quite frustrated with her and tempers start to flair. That starts to then threaten their ability to do their job and actually take care of their patients because of all the infighting. It becomes a sticky situation all around."

In a different interview with TVLIne, the actor conceded that a Meredith-Nathan romance was a possibility.

"Obviously it's a possibility," he said, before adding: "It's just as viable that I end up with anyone on the show. At the end of the day, my job is to serve the audience, and I do that by serving Shonda. If [a Nathan-Meredith romance] happens, I know there would be some strong feelings, positive and negative."

When questioned about the subtle sparks between Nathan and Meredith, the actor noted that showrunner Shonda Rhimes will definitely explore it if there is something to be explored.

"It's interesting. I didn't know how Ellen was going to play the [elevator] scene until we did the coverage, and I was like, 'Wow — is she flirting with me? Or is she just screwing with me?' And that's the kind of stuff that Shonda really likes to write to. And if she feels there's something to be mined there, she will. And if there's not then she won't," said Henderson.