Dick Advocaat has resigned as Serbia coach after Friday's 3-1 home defeat by Denmark in a Euro 2016 qualifier.
Under the Dutchman, who took over from Sinisa Mihajlovic in July, Serbia have picked up just one point from their opening three Group I games.
"I had never faced such a difficult situation in my entire career," the former Rangers manager, 67, said.
Friday's match in Belgrade was played in an empty stadium after crowd trouble in the abandoned game against Albania.
Serbia were awarded a 3-0 walkover after the home match in October but were also deducted three points, ordered to play two home qualifiers behind closed doors and fined 100,000 euros. However, the Serbian FA is appealing against the decision.
"The pressure, which was everywhere to be seen, was too much to bear by this team," Advocaat said.
Serbia play a friendly on Tuesday away to Greece, whose coach - former Chelsea boss Claudio Ranieri - is set to be dismissed following a shock 1-0 home defeat by the Faroe Islands in their Euro 2016 qualifier on Friday.