Ronald Koeman 'disappointed' by Southampton's loss at West Ham

Southampton manager Ronald Koeman says a poor start to the second half cost his side during their 2-1 loss to West Ham.

The Saints opened the scoring at Upton Park after Carl Jenkinson's own goal on 13 minutes, but the visitors couldn't add to their lead despite dominating the first half.

Supersub Carroll sinks Saints

Andy Carroll scored the winner as West Ham beat Southampton 2-1

Second-half goals from Andy Carroll and Michail Antonio saw West Ham complete their comeback, and Koeman believes his side were punished for not taking their earlier chances.

"In the first 20-25 minutes of the second half, we lost control. When Carroll came in, he changed the confidence of the West Ham team - because in the first 45, Southampton dominated," Koeman said.

"That's sometimes our problem. When you score one, they have belief to come back and they showed great character in the second half.

"I'm disappointed, but it was a great game of football. After less than 48 hours [since their last game], it's a compliment to both teams."

Koeman said he warned his side about Carroll at half-time, and believes the 26-year-old changed the game in West Ham's favour.

"We spoke at half-time and said that there will be a reaction [from West Ham]. They'll bring in Carroll, and they'll play the long ball, fight for second balls and be more aggressive," he said.

"But in the first 20 minutes, we lost easy ball possession and that gave West Ham the belief to come back. That's football, and that's the reaction of the opponent.

"If you play so well for the first 45 minutes and get so many chances, you have to score more than one - and we didn't.

"We showed today that we have a good team that plays good football, but we didn't get the result - but I am optimistic about the performance of the team."