The comments, by McConnell primary challenger Matt Bevin, came Tuesday morning in an interview with MSNBC's Chuck Todd.
"Have you listened to his support for McConnell in recent days and weeks and months? It's a little less than convincing. Here's what I'll say and you know this well," Bevin said. "You've followed this arena for a long time. Politics makes for strange bedfellows. Rand supported and endorsed Mitch long before I ever got in this race. To his credit, he's sticking with his word. He's a man of integrity. I think Rand is doing a good job. Whether people like him or dislike him, agree with him or disagree with him, he's largely doing what he said he would do when he went to Washington and that's a refreshing change of pace on our political landscape, it really is."
Paul has endorsed McConnell for re-election over Bevin, but at times there have been hints that the junior senator from Kentucky might not fully support his senior counterpart. In an interview with Glenn Beck in February, Paul said he supported McConnell because he was asked to support him.
"Uhh, because he asked me," Paul said. "He asked me when there was nobody else in the race. And I said yes."
Paul followed up with TPM after the interview to stress that he definitely supported McConnell.
"Mitch McConnell is an important ally and a conservative voice in Washington for the people of Kentucky," Paul said in a statement. "The commonwealth is stronger because of his service and I look forward to continuing to work with him."