Ronald Koeman says Saints believe they can beat Chelsea after securing a Boxing Day victory at Crystal Palace.

Confidence is high in the Saints ranks once again with back-to-back victories pushing them into fourth place.

They welcome Premier League leaders Chelsea to St Mary’s on Sunday and Koeman insists his side are not intimidated.

He said: “I am a coach who will try always to win and we respect our opponent, Chelsea, and they have fantastic football players but it’s 11 against 11.

“We try to do everything to win that game.

“We know it will be very difficult but it isn’t impossible, and that means that we will believe we can win against them.”

After picking up wins against Everton and at Palace, a comfortable 3-1 victory thanks to goals from Sadio Mane, Ryan Bertrand and Toby Alderweireld, Saints are buoyant.

However, they are facing a stern test as they now take on Chelsea, Arsenal and Manchester United in their next three league fixtures.

It is reminiscent of the run that brought them a hat-trick of defeats at the hands of Manchester City, Arsenal and Manchester United just a few weeks ago.

“We have to learn that maybe in one game our opponent was really the better team and that was City but Manchester United wasn’t, Arsenal wasn’t,” reflected Koeman.

“Normally Chelsea is the better team than we but it’s football and for them as well the second game in 48 hours and for everybody that is difficult.

“The three points (against Palace) makes the lads comfortable and we look forward to play against Chelsea.”

He added: “I think three points is always important because we like to win and we like to fight for the best position in the league. We know our programme for the next games but it has to be a challenge.

“Now on Sunday Chelsea is a little bit more comfortable with this win, that’s true.”

Saints will have captain Jose Fonte available again for the game, though Ryan Bertrand is ineligible to face his parent club.

They also had the added bonus that their comfortable position at Selhurst Park meant they could rest players.

“We had some weeks where we didn’t have all the players and that’s sometimes difficult because we don’t have that quality in numbers,” said Koeman.

“If we don’t have those kind of injuries we can change sometimes.

“Today Tadic was on the bench, Wanyama was on the bench, Shane Long was on the bench, Targett was on the bench.

“That’s also the quality of a team that means we can change if they show the belief and the spirit that we showed. That’s important for us because we need that in this programme, in these kind of games we need everybody.”