The Coventry City striker – who spent the second half of last season on loan at Fratton Park – has emerged as someone Gas boss Joey Barton would like to bring to the Memorial Stadium in a bid to bolster his attacking options next term.
According to the Sunday’s Mirror’s Darren Witcoop, Rovers are among a number of League One clubs interested in the 25-year-old, whose future at the Ricoh Arena looks in doubt.
Walker joined Pompey in January as Danny Cowley reshaped his own forward department in a bid to make his side more clinical in front of goal.
Out went John Marquis, Ellis Harrison and Gassan Ahadme, to be replaced by the Sky Blues front man and Aiden O’Brien.
But while the latter impressed with five goals in 17 appearances, Walker endured a miserable south coast stay.
He netted just one goal in 15 outings as he struggled to make a Pompey impact.
Indeed, the former Lincoln ace failed to feature in any of the Blues’ last six games, despite being named on the bench.
His last appearance came in the 1-0 defeat at Cheltenham on April 9.
Walker’s January arrival could potentially have led to a permanent arrangement at Fratton Park, yet such plans have long been scrapped.
If the striker moves to the Gas, he could link up with Pompey target Aaron Collins, who last week spelt out his intention to remain at the Memorial Stadium for their League One return.