Wigan defender Antolin Alcaraz has accepted a Football Association charge for spitting at an opponent during Sunday's 3-1 defeat at Wolves.
The 29-year-old Paraguay international centre-back will now serve a three-match suspension.
Wigan said in a statement: "The matter will be treated with utmost seriousness and be dealt with internally, according to the club's code of conduct."
TV cameras caught Alcaraz spitting at Wolves defender Richard Stearman.
It sparked a mass brawl and earned the wrath of Wolves manager Mick McCarthy.
McCarthy, who saw Jamie O'Hara, David Edwards and Stephen Ward score the goals that set his side on their way to a third victory of the season, said: "If it has been shown, that is unacceptable behaviour.
"I only had it happen to me once and the player didn't come too close to me for a long time."
It was initially thought Alcaraz, who joined Wigan from Club Brugge in the summer of 2010, had spat at centre-back Christophe Berra.
But fellow defender Richard Stearman 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."
When he was asked if he was spat upon, he replied: "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."
Wigan are currently bottom of the Premier League table with only five points and will be without Alcaraz for key matches against Blackburn, Sunderland and Arsenal.