DeMarco Morgan — the GMA3 anchor who replaced T.J. Holmes — has his newsroom in a tizzy over some pics he posted showing himself in bike shorts … ’cause it left an impression.

The ABC daytime cohost — who was tapped to fill in for T.J. after his affair with co-anchor Amy Roback — posted pics late last month in tight biker clothing that left little to the imagination … and which definitely drew focus below the belt.

While many online cracked jokes at the racy pics or made comments about DM’s package, which was clearly on display underneath, sources at ABC say much of the org’s rank and file is not amused — in fact, we’re told there are a lot of staffers there who are kinda irked.

Sources with the news org tell TMZ … several of the network’s anchors and correspondents have urged Morgan in recent days to take down the photos from his feed, but we’re told he hasn’t — because he apparently feels they’re overreacting to the whole sitch.

We’re also told there are some inside ABC who feel the pictures are embarrassing not just for DeMarco, but the entire news organization — especially in light of ABC News President Kim Godwin recently exiting the company herself … as he was her pick for the job.

We’re told Morgan’s not facing repercussions at this point — but that doesn’t mean people aren’t making a fuss about it there in the building … because we’re told they totally are.

BTW … TMZ has seen a copy of ABC News’ morals clause — which states an employee will act with due regard for public morals and conventions and won’t do anything that makes ABC the subject of contempt, scandal and ridicule

And … ABC’s parent company, Disney, has its own clause on this same topic that reads, “Be responsible in your use of social media. Use online tools in a way that is consistent with our company policies.” Unclear how the Mouse House is reacting to Morgan’s post.