Pompey are showing interest in Peterborough United midfielder Anthony Grant, according to the club's director of football.
Barry Fry told the Peterborough Telegraph that the Blues are one of several clubs tracking the 31-year-old.
Blackpool, Shrewsbury and Lincoln also reportedly have Grant on their radar.
Fry revealed the Posh have given the London-born talent permission to speak to a club, although a fee has yet to be agreed.
The director of football said: 'Numerous clubs have shown an interest in him including Lincoln, Shrewsbury, Portsmouth and Blackpool.
'Anthony has been given permission to speak to a club without a fee yet being agreed.'
Grant made 48 appearances for the Posh last season, helping them to a ninth-place finish in League One.
He graduated through Chelsea's academy in 2004 and made a solitary appearance for the Premier League outfit in a 3-1 win over Manchester United in April 2005.
Grant has also represented Southend United, Stevenage, Crewe and Port Vale during his career.
He has a year left on his Peterborough contract after moving to London Road for a six-figure fee in January 2017.