Sidlow made his debut for Liverpool on 31 August 1946 in a league match at Bramall Lane and kept his first clean sheet for the club, with Len Carney scoring a late goal for the Reds in the 90th minute.
Even with the competition, Sidlow was given the position, which he held for 34 of the 42 games in a season that saw Liverpool win their first championship in 24 years.
Sidlow's former employers, the Wolves, needed just a point to win the title and Liverpool had to face them at Molineux.
His performance in this pivotal game against his former club is often considered the high point of Sidlow's Liverpool career.
Charlie Ahcroft and Russell Crossley took over for four games before Sidlow came back in to play his last match for the club.
Things didn't go well for Sidlow and the Reds as The Magpies went back to St James' Park with the points after a 4–2 win.