Danny Cowley is keen on the Welshman, who played a key role in firing Joey Barton’s side into League One in dramatic fashion.
But the Blues boss has to decide whether to pursue a move for the 24-year-old - or whether he feels he can find better value lower down the league pyramid.
Collins made a big impression at the Memorial Stadium, firing in 17 goals this season to help the Gas to a dramatic final-day promotion.
The first of those finishes didn’t arrive until November, after he settled in at his new club after arriving from Forest Green last summer.
But his season caught fire from there, with his pace and ability to finish with either foot catching the eye.
Cowley and his recruitment team have been watching a player who would bring the speed he is desperate to add to his attacking options, as he faces a summer in which additions up front will be a priority.
Pompey don’t have a senior forward contracted for next season, with the Londoner indicating he’d like to have four to pick from by the time his second full season at the Fratton helm begins.
Collins would command a fee, with a year remaining on his existing Bristol Rovers agreement.
Pompey are also certain not to be the only team impressed with his development this term.
That leaves Cowley having to consider where he can best utilise his playing budget this summer.
Pompey have stated a transfer policy of landing young players on the rise, who they can develop and sell on for a profit.
With Cowley and his staff scouring the non-league game, it may be he believes he can unearth out-of-contract options there.
Meanwhile, players being released from academies in the top two divisions may present an alternative source of talent.