The incident occurred in the 83rd minute of Wolves' crucial 3-1 home victory and sparked a brawl involving several players from each team.
Referee Lee Probert took no action but Stearman confirmed that Alcaraz had spat in his direction after it was initially thought it was aimed at Christophe Berra.
Stearman was reluctant to talk about the incident but said: "It wasn't Berra, I'll give you that, but I don't think it's right for me to talk about it at the moment."
Asked if he had been spat at, Stearman added: "Yes, but I'm not going to speak about it."
"I can confirm it happened and that it was me rather than Berra. I'll let other people talk about it and let other people deal with it. I won't push for anything, it's one of those things - but it's not nice.''
McCarthy said: "Spitting is taboo if that's what happened. I only had it happen to me once and the player didn't come too close to me for a long time after that.
"If it has been shown, that is unacceptable behaviour and anyone here who was spat at would act accordingly. If that has happened, he shouldn't be doing it."
David Edwards, who scored Wolves' second goal, said: "That is out of order. That shouldn't be brought into the game and hopefully he should be pulled up on that. I'm sure with the television footage as well, some sort of action should be taken."
Wigan boss Roberto Martinez would only say: "I haven't seen (the replays) yet. If that is the case, I'll look into it and I'll find out."
McCarthy said: "It all looks different with one win and we knew that would be the case but it was much needed. We can't keep going on saying we did alright. You've got to win a game and today was the one we needed to win against Wigan.
"What pleased me most was the reaction after taking the lead and then conceding a penalty. It was the great togetherness of the place. The crowd were brilliant. We conceded the penalty and they got the lads going again.
"Then we came out second half, and it was a great response by all of us. That was nice. There was just a real nice togetherness in the place and we've got to have that."
Martinez was left to rue a host of missed chances as his side slumped to an eighth successive Premier League defeat with Ben Watson netting their consolation effort.
He said: "We couldn't get properly going today. We allowed the first goal to affect all the performance too much. We had a great chance in a one v one situation (from Hugo Rodallega). We usually take those and then they went up the other end and scored a little bit of a soft goal.
"From then on it seemed the day was going into Wolves' hands which was a little bit disappointing. They were able to sit back and hit us on the counter and then we gave them another two soft goals."