Walcott could make his first Premier League start since April for the visit of West Brom and the 28-year-old is raring to go.
He could only watch his new team-mates train at Finch Farm on Wednesday as the deal had not been completed, and Friday will be his first full session with Sam Allardyce's squad.
"I have a new manager I have to impress and get the ball rolling," said the forward, who was the third-highest goalscoring Englishman last season with 19, behind only Tottenham duo Harry Kane and Dele Alli.
"After speaking to the gaffer and particularly Wayne (Rooney) as well, I felt the club was on the up with a manager who seems to get the best out of players.
"I want this club to push on and reach the levels it can and you get the sense that it is a club that financially can attract big players.
"I got a sense from Wayne he was hungry and the club was eager to push on and that is why he wanted to join.
"He felt it was the right place and I totally agree with him."