Ronald Koeman: Everton boss criticises Ross Barkley and Romelu Lukaku

Everton have lost three of their last five Premier League games

Everton boss Ronald Koeman says he has become "worried" by his side's performances after a run of one win in eight Premier League games.

Koeman had an unhappy return to his former club Southampton as Everton lost 1-0 at St Mary's Stadium on Sunday.

The Toffees had one shot on target and Koeman said the performances of midfielder Ross Barkley and striker Romelu Lukaku were "not good enough".

"We need to be sharp, react fast to second balls," added Koeman.

Everton boss Ronald Koeman was unhappy with his team's start against Southampton

Southampton's winner came after just 41 seconds and it was not until the 93rd minute that his side had an effort on target.

Koeman added: "It's incredible. You start a game to control a game and we didn't. We had bad defending positions for the cross. That [goal] made it difficult and a different game.

"The whole first half was not good. We had problems with Southampton's strikers, and that's strange because we know how they play.

"I'm not worried about results, I'm worried about what I see on the pitch."

Lukaku had just two touches in the Southampton penalty area - as many as he had in his own - as Everton struggled to test Saints goalkeeper Fraser Forster.

Despite their poor run, Everton remain seventh in the table.

Three of their next four league matches are at home to Manchester United (4 December), Arsenal (13 December) and Liverpool (19 December).