Foley joined the cast last season as Henry, a patient who ended up marrying Teddy (Kim Raver) for her medical insurance.
Rhimes has now revealed that he will continue to have a role in upcoming episodes.
"[He'll stay for] a decent amount of time," she told TV Line. "We'd keep him around forever if we could."
Meanwhile, Raver revealed that Henry and Teddy will continue to date after getting together in the latest season finale.
"We start out [the new season] where they're madly in love," she said. "They're really very, very close right now. I definitely think for Teddy, Henry completes who she is and what she needs."
Raver added: "The great thing is that it's reciprocated. It's sort of the first time [that's happened for her]. It's a really big deal."
Grey's Anatomy will return for a new season on September 22 on ABC.
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Watch some clips of Scott Foley and Kim Raver in the latest season finale of Grey's Anatomy below: