Premier League Preview: Burnley v Southampton
Successive defeats against Manchester City, Arsenal and Manchester United have seen Southampton, who began the season so impressively, drop out of the Premier League's top four.
Yet, when asked if a meeting with 19th-placed Burnley came as a relief, Koeman was quick to guard against complacency.
"We know [in] the Premier League, there isn't an easy game. You have to fight for the points," said the Dutchman.
"We go game to game. It may be more physical than Monday against Manchester United.
"Burnley are a different team, have a different type of player. We know it will be difficult."
Toby Alderweireld is set to regain his place in the heart of Southampton's defence after missing the 2-1 loss to United with a hamstring problem, while James Ward-Prowse, who fractured a foot against Swansea City in September, could be on the bench.
However, Jack Cork - a former Burnley loanee - remains sidelined and Morgan Schneiderlin is a doubt, with Koeman hopeful the Frenchman will be fully fit for Tuesday's League Cup quarter-final tie at Sheffield United.
With Manchester United not in action until Sunday, fifth-placed Southampton will move back into the UEFA Champions League qualifying places if they triumph at Turf Moor.
Burnley saw a four-match unbeaten run come to an end last weekend when they went down 2-0 to fellow strugglers QPR.
Sean Dyche's men have avoided defeat in their last three contests on home soil, though, and know victory this weekend could lift them out of the bottom three.
Dyche must again make do without defender Stephen Ward, who is set to be out for at least six weeks after injuring his ankle against Newcastle United on December 2.
Matt Taylor (Achilles) and Michael Duff (calf) are also unavailable and Dyche has called for caution regarding Sam Vokes, who continues to build up his fitness after suffering a serious knee injury in March.
The Wales striker completed 90 minutes for Burnley's development squad on Tuesday, but will not feature this weekend.
"Sam is feeling better physically and mentally. It's a big marker for players to get their first 90 minutes," said Dyche.
"It feels like pre-season for him at the minute. You come back from close-season, get back into your games and the big marker is when you get the first 90 minutes under your belt and how you feel.
"It's as important as how you play. And for Sam at the minute, it really is the mentality of playing for 90 minutes and then we take it forward from there."