Per the Daily Beast -- which cited insiders with knowledge of the situation -- Lemon will miss Monday's show for 'CNN This Morning' ... and will simply enjoy the holiday, President's Day. It's being reported that his upcoming absence was not planned prior to Thursday.

Rather than Don there, the two anchors that'll be holding it down are Poppy Harlow and Sara Sidner ... with Kaitlin Collins, another regular co-host, being stationed in Poland for coverage. Monday's on-air lineup was sent out to CNN staffers this weekend, so says DB.

That's not all ... according to the outlet, DL's position at CNN is apparently up in the air at this point -- with one of the cited insiders saying his time there is being discussed at the highest levels, while also adding ... "He is a constant distraction."

Another report by FOX News cites yet another CNN source, who says Lemon should return by Tuesday, but not even that is guaranteed ... because, apparently, it'll depend on "where his head is at." It's also unclear if this a straight up suspension, or if it's on Don's terms.

In any case, it sounds like there might be changes in the near future. We'd already reported that Don hopped on a staff call Friday to apologize, but it did not go over too well on the receiving end ... with sources telling us many took it has him patting himself on the back.

CNN Worldwide CEO, Chris Licht, is also said to have been pissed about the Nikki Haley quip, reportedly saying ... "His remarks were upsetting, unacceptable, and unfair to his co-hosts, and ultimately a huge distraction to the great work of this organization."