Pompey are chasing former Walsall striker Craig Westcarr.
The 29-year-old netted 17 times for the League One club last season to finish as their top scorer.
But he was not offered a new deal at the end of the campaign and the free agent has been attracting plenty of attention.
It is understood Andy Awford has now stolen a march, ahead of fellow admirers Port Vale, to close in on Westcarr’s signature.
The Blues are in the market for at least one striker and are also keen on recruiting attacking options who can play as one of the three behind a lone forward.
Westcarr fits that description, with former Saddlers manager Dean Smith stating he believes his best position is linking up play behind the centre-forward.
The former Nottingham Forest trainee’s departure from the Bescot Stadium at the end of the season was seen by a shock by many Walsall fans.
He had scored 22 goals since joining on a free from Chesterfield in January 2013, but it was last season which saw him truly shine.