Chelsea are reported to be interested in the Germany international and Leverkusen's director of sport Rudi Voller flew out to London last week to hold talks with the Blues.
However, no transfer has yet been agreed and Holzhauser wants to have time to act if Schurrle does decide to leave.
"Last year, we had an enquiry, but it came very late," he said. "This time, it is still relatively early, which is good.
"Andre is, alongside Mario Gotze, one of the best young players in Germany and if he leaves us, we will want cover for him. We want clarity as soon as possible."
According to Holzhauser, the bid his club have received for the 22-year-old does not yet match their expectations, which is why his appeal is not aimed only at Schurrle but at the Premier League club, too.
"We are still quite a long way apart in terms of certain details," he told Germany's SID agency.
"There are always two options: either Andre stays here or he leaves."
The sooner Holzhauser knows which option it will be, the sooner he can make plans for next season, with Bayer Leverkusen set to play in the Champions League once again.