The striker will be aged 17 years and 312 days when Wales line up in Vienna, and would beat the previous record - set by Ryan Giggs - by nine days.
Cotterill said: "This week has been special for me, I've had the opportunity to stake a claim for a starting place.
"John Toshack has been giving me plenty of advice, and I think I've done well in training.
"I'm hopeful of being on the bench, and if I am you'll never know what could happen."