The 25-year-old left the pitch after applauding the travelling support and made his way down the tunnel, despite being called over by manager Oliver Glasner.
What appeared like a standoff with the FA Cup-winning boss, who called Guehi several times as he led the team towards the away end, was simply a miscommunication.
Guehi had already acknowledged the Palace fans before making his way off to settle his anti-doping test, while Glasner guided the rest of the squad to the away end.
🗣️ "It's like the new garlic bread"
Roy Keane's thoughts on that Oliver Glasner and Marc Guehi interaction at full-time of Chelsea vs Crystal Palace... pic.twitter.com/Ntqh24Mvfy
— Sky Sports Premier League (@SkySportsPL) August 17, 2025
Premier League players are randomly chosen for such tests throughout the season and can be asked to provide a blood or urine sample after matches, at training sessions, or even at home.
Former Republic of Ireland international Roy Keane had strong comments about the incident following the match on Sky Sports, which caused rampant speculation on social media.
"Why has this happened over the last year or two? Where managers come on to the pitch and shake hands with everybody and the opposition players.
"A player has just had a tough match, he's physically exhausted, and the manager is just trying to go and have a little chit-chat knowing that there's talk of him leaving.
"As a player you don't want to get involved in that as well. I've had managers come up after the game and you're going, 'what's up with you? Let's get down the tunnel. If you want to have a chat, we will do it inside'.
"Managers are always wanting to do something on the pitch. That's all come in the last few years. What happened to years ago when the manager would shake the other manager's hand and walk down the tunnel?
"It's the new thing. It's the new garlic bread. Just get down the tunnel, it's just a league match."
Despite the mix-up, Glasner and Palace skipper Guehi are understood to have a strong relationship.