The actor took to Twitter to confirm the news of his exit, shortly after news broke he was exiting the NBC medical drama, along with co-star Norma Kuhling.
"Sorry to say that this is true," Donnell wrote on Twitter, sharing the link to the Deadline story that fire broke the news. "I love my [ChicagoMed] [OneChicago] family dearly. And a special thank you to all the fans that have made these last four seasons so amazing."
It’s been an honor to be a part of such a great trio of shows and in the @WolfEnt family.
I know that there’s great things coming for Season 5 and I can’t wait to see what they are along with all you fans.
xoxo— COLIN DONNELL (@colindonnell) April 19, 2019
He added: "It's been an honor to be a part of such a great trio of shows and in the [Wolf Entertainment] family. I know that there's great things coming for Season 5 and I can't wait to see what they are along with all you fans."
Fans of the NBC television franchise responded to Donnell's note sharing their grief after news of his character exiting the series.
"Not happy! You were the main reason I watched," one user commented.
"Sad, but honestly, this one I saw coming for awhile. I've read between the lines, you hated being apart from your wife and that's understandable. I wish you the best of luck in whatever you do next. I hope this isn't the last we see of Dr. Rhodes," Another user wrote.
"It's absolutely heartbreaking to lose Connor as a characters (sic) and I've generally grown up with Chicago Med. I'm so thankful that we've had the opportunity to see you in action - it's been breathtaking and awe inspiring. Thank you Colin," a third user responded.
Along with Donnell, who has been on the show since the series premiere in 2015, Chicago Med will also say goodbye to Norma Kuhling. The actress played Dr. Ava Bekker on the medical drama since the Season 2 finale.
Chicago P.D. will also lose longtime series regular Jon Seda, who played Detective Antonio Dawson on Chicago Fire, P.D. and the shortlived Chicago Justice.
The news of the One Chicago exits comes a day after news surfaced Chicago Fire stars Jesse Spencer and Taylor Kinney officially signed new deals to stay with the firefighter drama for two more years.
All three Chicago shows were picked up for new seasons at the network in February. The shows airs Wednesdays starting with Chicago Med at 8 p.m. ET on NBC.