The Gunners confirmed their place in Thursday's draw for the Champions League group stage and a predicted extra £10million in revenue with a 5-0 aggregate win over the Czech champions.
Walcott produced a jinking run and perfect delivery to set up the first goal for Tomas Rosicky before late strikes from Cesc Fabregas and Eduardo Da Silva completed the scoring at the Emirates Stadium.
Wenger believes the £10million signing from Southampton will be lethal when he is converted from winger to striker and insists he posses qualities rarely seen in English players.
The Arsenal boss said: "Theo had a good first half. He can be decisive.
"He's very direct, quick, is a good crosser and finishes well.
"He's improving his link play and is more aggressive. When he uses all the assets he has he will be dangerous for everybody.
"Once he plays through the middle he will make good runs and get behind defenders.
"Close to the line you need better technique and his greatest quality will be the runs he makes behind defenders.
"In the future he'll be used more as a central striker. He can make a difference for England because there are not many strikers in this country who have his qualities or pace.
"If a defender is one yard behind him Theo will never get caught. He makes good runs along the line of the defence and he will be able to use that more when he plays through the middle.
"But it's good for him to learn the job on the flanks. All the young players can show their top quality in the Champions League."
Wenger added: "This team has already been in the Champions League final.
"Lets get through the group stages and then we'll see how far they can go this time round."