Southampton have surprised many with a superb start to the campaign, rising to second in the table after nine matches.
A stunning 8-0 win over Sunderland was followed by a battling 1-0 victory against Stoke City last Saturday, while Wednesday's League Cup triumph over Mark Hughes' men secured a quarter-final spot.
With nine wins from the last 10 matches in all competitions, Koeman's men are in excellent form, but the trip to the KC Stadium represents their third fixture in eight days.
"The lads are showing great ambition," the Dutchman said following the midweek win.
"They will be tired, but if you're winning you're not so tired."
"It's a purely selfish thing getting that first goal under your belt," he said. "I'm obviously delighted to get it.
"It wasn't getting me down too much, but it's always easier when the team is doing so well."
That run has left Steve Bruce's side 10th in the table and centre-back Alex Bruce noted the huge upturn in the club's fortunes over the past two seasons.
"It is unbelievable to think how far we have come," he told The Hull Daily Mail. "The supporters must agree with that. Things have changed so much since I first came here."
