Adams and his co-star quit the drama after the seventh season as Markle went off to become a Duchess and he chose to pursue other projects, but now Patrick is heading back for the final run of shows.
Markle, aka the Duchess of Sussex, will not be returning but Adams insists her character, Rachel Zane, has not been killed off - and the popular legal eagle will be mentioned in the upcoming ninth season.
"For (my character) Mike (Ross), this is just a trip to New York," he tells Entertainment Tonight. "He's in Seattle, they (Mike and Rachel) are building their life together, it sounds like he's doing well."
"There's phone calls with Rachel saying, 'Goodbye, I love you', and, you know, I think there's some obvious acknowledgment that she's still there and a part of the show... I promise you they're happy."
Both Adams and his former TV love interest have become parents since departing the show - Meghan welcomed her first child with Prince Harry in May, while Adams and his wife, Troian Bellisario, became parents to a baby girl in October.
"Yeah, it's weird. We all have kids now," Adams laughs. "It's fantastic. I mean, it just changes everything in your life. It gives you a new purpose."
Meanwhile, the Duchess of Sussex is expected to make her first red carpet appearance since giving birth to son Archie at "The Lion King (2019)" premiere in London on Saturday, July 13.