Attwell played his first competitive match for Burnley on 9 November 1946 in the 1–1 draw with Luton Town. He went on to play 22 league games during his debut season, as well as six matches in the FA Cup as the side reached the final of the competition. He was in the starting line-up for the final as Burnley lost 0–1 to Charlton Athletic. Attwell remained manager Cliff Britton's first-choice right-half throughout the following season, missing only four games of the campaign. He scored his first goal for Burnley on 24 April 1948, netting the second goal in the 2–0 away victory over Chelsea. During the 1948–49 season, Attwell made 38 first-team appearances for Burnley and scored five goals (four of them penalty kicks). His performances earned him a call-up to the Football League representative side for a match against the Scottish League in 1949. Following this, Attwell was widely expected to be selected for the England national football team, but he was never chosen to play for his country.