Walcott's situation has been the subject of continued speculation in recent months, with negotiations between the club and player ongoing.
It is understood Arsenal are ready to make the 23-year-old one of the highest-paid players at the club with a £90,000 per week five-year contract.
Wenger said: "We are on a good road. In this situation as long as nothing is signed, you are cautious. However, I am optimistic we will get to a happy conclusion.
"Discussions are progressing slowly, but smoothly. We still work on the transfer market, but do not want to bring in average players."
Arsenal have been linked with a string of players including Barcelona's David Villa.
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