Sunday’s 2-0 win over Aston Villa meant that Cech has now kept 169 clean sheets in the Premier League, which has equalled the record held by David James.
And Walcott has praised the summer signing from Chelsea for his immediate impact at Arsenal.
“From when we signed him, we all knew how good he was [after] what he achieved at Chelsea,” the forward told Arsenal’s official website.
“On a personal level, for him it’s great. He’s changed us completely in that back four. He’s a talker, he believes in us all.
“That’s why he wanted to join us and having with that presence behind you is always nice to have. He’s very commanding, he’s a leader in the dressing room as well, he always likes to talk.”