Sanath Jayasuriya branded his Sri Lanka side a bunch of "amateurs" after succumbing to a 53-run defeat to minnows Kenya.
Jayasuriya called on his team to forget the defeat and refocus
The Sri Lankan captain was fuming after his side were surprisingly outplayed in Nairobi to reduce their chances of qualifying for the Super Six stage of the tournament.
He said: "I think it's one of the worst matches I've ever played; 211 is an attainable total but that was disappointing.
"We did not play like professionals today, we played like amateurs.
"We batted badly and our middle order didn't click. This is my and the team's worst day in cricket."
Sri Lanka, winners of the tournament in 1996, have now dropped to second in Group B.
And they must win at least one of their remaining games against the West Indies or the South Africa to have any chance of making the next round of the tournament.
Jayasuriya admitted: "I'm worried about the middle-order batting.
"This was the best opportunity they got before the big matches come and they didn't prove themselves.
He added: "We didn't play well, and this puts us under pressure to beat the West Indies in Cape Town. That match, and the one against South Africa, will be a big test of our character."