The Belgium international has scored just once in the last six Premier League matches, is currently five league games without a goal and has not registered a shot on target in three of his last four outings.
But with next-highest scorer Ross Barkley (three) relegated to the bench against Manchester United last weekend and winger Yannick Bolasie, who has provided four assists for Lukaku, now out for a year with knee ligament damage, the manager has put the emphasis on the rest of the team to step up.
"It's a little bit the story of strikers," said the Dutchman.
"You can have a good run of scoring goals and then have a bit of time where you don't really get big chances to score.
"The players around him need to create more and he can improve in his movements - it's a team question to create more chances.
"We know how we need to create chances for him
If he gets the chances, we know he will score goals.
"We need movements around the player and that was the reason why Kevin Mirallas played closer to Romelu against Manchester United
He needed that support as a striker."
Everton have won just once in 10 matches in all competitions but despite taking two points from their last four games they remain in eighth place.
However, their away record is poor with just seven points out of a possible 21 on the road, having not won since mid-September at Sunderland.
If they were to lose at Watford they would be overtaken by their 11th-placed opponents, who have lost three out of the last four themselves.
Koeman saw positives in the 1-1 draw against United, secured via an 88th-minute Leighton Baines penalty, but accepts things have to pick up in the next few weeks with games coming thick and fast.
"One point every time is not enough
The best confidence is to win the game," he added.
"The team performance against United was good but we know we need to win - it is the same problem for most of the teams.,
"Watford are also in a difficult situation as they have not had the results they expected, so we know it will be a tough game coming up."
Failure to win against Watford would increase the pressure with trips to Arsenal and Liverpool due before Christmas, but Koeman is remaining calm.
"It is not about the schedule
Sometimes maybe you get a win against a big team and not against a lower team," he said.
"We don't have a good away run at the moment and we need to change that."
Source : PA