The Dutchman was not happy with the officials after seeing his side let slip a lead at St Mary's as the reigning champions came from behind to take all three points
Southampton manager Ronald Koeman hit out at referee Martin Atkinson for ignoring his linesman flagging for a foul in the build-up to Chelsea's equaliser in a 2-1 Premier League defeat.
Having seen goalkeeper Fraser Forster set a new club record for minutes without conceding a goal in the top flight as he reached 667 in the 34th minute, Southampton took the lead through Shane Long.
Long pounced on a poor defensive header from Baba Rahman to break the deadlock but Chelsea dominated in the second half, with Cesc Fabregas' cross-cum-shot curling beyond Forster - who was finally beaten after 708 minutes - in the 75th minute.
A minute from time Chelsea completed the turnaround, as Branislav Ivanovic powerfully headed home Willian's corner.
But Koeman was not happy about Chelsea's first goal, which came after Atkinson had overruled his linesman, who flagged to signal a foul by Kenedy on Southampton defender Cedric Soares.
Koeman told BBC Sport : "I don't understand that. The linesman is the closest to the situation. If it is a fault by Kenedy then you have to listen to the linesman. That's why you have linesmen - to help you.
"Chelsea's equaliser was not a shot - it was a cross. Then 2-1 came from a set-piece - normally we defend these situations well. Ivanovic was stronger than one of our defenders.
"We had a lead before half-time, which is always good, we defended well and they didn't create a lot.
"But I think the problem in the second half was we didn't have domination and went back too much, letting them have more ball possession."
- Goal