Joey Barton has led the Gas back to the third tier with automatic promotion in League Two and now thoughts are turning to the new campaign.
Bristol Rovers have been linked with Walker, who is on the books at Coventry City.
Walker spent the second half of the season in League One on loan at Portsmouth.
The attacker is on big wages by League One standards at Coventry and it is suggested that the Gas targeting him signals their willingness to spend this summer.
Barton will be keen for Bristol Rovers to build on their success this term by carrying the feel-good factor over into next season and he is already looking to bring Elliot Anderson back on a fresh loan spell from Newcastle United.
Walker came through the youth set-up at Nottingham Forest and had a series of loan spells away from the Tricky Trees before a permanent move to Coventry.
The forward scored 14 goals in 29 games at League One level with Lincoln City in the 2019/20 season.
