Matt Clarke is attracting interest from two Premier League clubs, reports suggest.
According to the Daily Mirror, Brighton & Hove Albion and Watford are both keeping tabs on the 21-year-old.
Clarke moved to the Blues from Ipswich on a three-year deal in July 2016, after spending the 2015-16 campaign on loan at Fratton Park.
The defender has made 83 appearances to date for Pompey and was a key member of the League Two title-winning side last term.
Clarke has also featured regularly since Kenny Jackett was appointed manager after returning from a hamstring injury he picked up in pre-season.