The 24-year-old joined the U's in 2024 after leaving Derby County, where he progressed through their youth academy and into the first team, playing 173 times and scoring 20 goals.

The central midfielder played 44 times for Derby in the 2023/24 season as they also won promotion from League One. 

Sibley spent the second half of the 2024/25 season on loan at League One side Rotherham United.