The Notorious switched from MMA to boxing back in 2017 for a fight with the legendary Floyd Mayweather but his skills in the ring didn't impress Garcia, who suggested that he would struggle to beat the YouTuber Jake Paul.
Garcia told SportsJOE: "People can say whatever they want. When I watched Conor fight Mayweather. Conor can't box. He can't box.
"If Conor was smart, he'd ask Jake Paul to go in the octagon with him. If you're the bigger star you should do that because Conor is not that good of a boxer in my opinion. I understand that it was against Floyd Mayweather, but your punches didn't even look good. Like when you were throwing them, they didn't have no torque on them."
Garcia says that McGregor will lose if he fights anyone "good" and would bet thousands that the Irishman would struggle against Paul.
He said: "Can you make improvements? Of course, anybody can. How much can you? I don't know. He steps into the ring again with anybody good, he's not going to win. He's just not. I think him and Jake Paul, if he brings the same fight he brought to Floyd against Jake Paul, that's more competitive. I promise you.
"I'll put a hundred thousand dollars he won't knock out Jake Paul. You can mark it down right now. I'll put a hundred thousand he won't be able to knock out Jake Paul. Will he beat him? Maybe. He won't knock him out though."