The cruel post, which most outlets including HELLO! are not sharing, sparked outrage online, including from Patrick who penned a lengthy tweet against the comment.
He wrote: "Oh @pnehlen – you're a sad and sick man with no sense of shame or class. Get a life. And don't go anywhere near MM – she's got more power, strength, honor and compassion in her fingernail than you'll ever know in this lifetime. Way above your weight class."
Meghan and Patrick became good friends after playing love interests Rachel Zane and Mike Ross on the popular American legal drama. Following the news of Meghan and Harry's engagement in November, the actor was quick to send a heartwarming tribute to his friend.
He posted a photo of Meghan in character as Rachel, writing: "Playing Meghan’s television partner for the better part of a decade uniquely qualifies me to say this: Your Royal Highness, you are a lucky man and I know your long life together will be joyful, productive and hilarious. Meghan, so happy for you, friend. Much love."
Before Meghan and Harry tie the knot, fans are expecting Meghan and Patrick's characters will get married before season seven of the show wraps up.
Speaking about leaving her acting career behind her, in her first joint TV interview with Prince Harry, Meghan said: "I don't see it as giving anything up, I just see it as a change… It's a new chapter. Right. And also keep in mind I been working on my show for seven years. So we're very, very fortunate to be able to have that sort of longevity on a series and for me, once we hit the 100 episode marker I thought, 'You know what? I have, I have ticked this box'… I feel really proud of the work I've done there."