Arsenal striker Robin van Persie may be out for season.
The 26-year-old Dutchman suffered an ankle injury while on international duty in November and was initially expected to return to full fitness in six weeks.
But instead surgery was required, and Wenger concedes the problem will keep Van Persie sidelined for several more months.
“If you are very positive you would say (he’ll be back in) April,” Wenger told the club’s website. “If you’re a bit cautious you say May. It is virtually the rest of the season.
“Personally I thought ‘Let’s put it in my head that he will not play again this season and hope that I will have a good surprise’.”
The Netherlands start their World Cup campaign in South Africa with a Group E tie against Denmark on June 14.
Arsenal are seeking compensation from the Dutch Football Federation as they believe they initially misdiagnosed the injury. The KNVB denies any wrongdoing.
