Barring a miracle, Sabathia's career ended Thursday night ... when the 39-year-old star pitcher was forced to leave Game 4 of the Yankees-Astros ALCS game when his knee buckled on the mound. The Yanks are 1 game away from elimination ... and CC's retiring after this season.

So, when former longtime manager Joe Girardi -- who managed CC from 2009-2017 -- was asked to talk about the legendary hurler during his MLB Network TV gig, it got emotional.

"That was not the way I wanted to see it end for him."

"CC, you're a Hall of Fame pitcher that was as tough as any man I was ever around, what you went through on a daily basis to just be able to get on the mound."

"You were a great husband. You were a great father. You were probably the greatest teammate I've ever been around because of your ability to pull all 25, sometimes all 50 people together in the clubhouse."

Girardi continued, and this is where it really gets emotional ... "And, you were the guy I always wanted on the mound when we needed a win. And, it was a privilege for me to manage you for 9 years. I love you, man."

WE'RE NOT CRYING, YOU'RE CRYING!!!!

If this is it for the 251-game winning, 6x All-Star and 2007 AL Cy Young winner -- and it certainly looks like it's a wrap -- Sabathia's next stop is likely Cooperstown