Townsend has been with Spurs since nine years of age.
"It's a massive night and will be a special occasion against Shamrock," Townsend said.
"I believe I have the ability to break in to the first team. This is the perfect chance for me to show the manager what I can do and show him that I can play a part in the future of this club.
"The manager watching us in training and in the reserves is one thing, but playing in the Europa League against teams like Shamrock and PAOK Salonika in front of massive and hostile crowds is different."