Hardy is set to fight Allen Crowder at UFC on ESPN on Jan. 19 -- the same night Ostovich will return to the Octagon after her domestic violence incident.

As we previously reported, Ostovich was hospitalized last month following an altercation with her MMA fighter husband Arnold Berdon, who was later arrested and charged with assault.

Some critics are upset with the UFC -- claiming the organization is tone deaf putting Hardy and Ostovich on the same card because of Hardy's past domestic violence issues.

FYI, Hardy was found guilty of domestic violence by a judge in 2014 -- but the conviction was thrown out in 2015 when he appealed to have the case go in front of a jury ... and his accuser stopped cooperating with prosecutors.

Dana White has previously told us he's spoken with Hardy about the incident -- but he's convinced Greg is a changed man.

So, how does Greg's new opponent feel? We spoke with Crowder -- who's fought against beasts like Curtis Blaydes and Justin Willis -- and he spelled it out for us.

"I definitely want to win this fight for [Ostovich]. I'm very against men beating women. And, I'm definitely not a woman, so he's gonna have a lot harder time with me then he did the last person."