Transfer-listed Cobblers left-back Raheem Hanley was given permission by the club to play in a pre-season friendly for Sky Bet League One rivals Oxford United on Wednesday night.
The former Swansea City man has been deemed surplus to requirements by Town boss Justin Edinburgh, and was told at the end of last season he could leave the club, along with Harry Beautyman, Jak McCourt and Rod McDonald.
Beautyman, McCourt and McDonald have all moved on to Stevenage, Chesterfield and Coventry City respectively, but left-back Hanley has yet to find himself a new club.
Oxford United have shown an interest in the player, and he was named as a trialist for their friendly against Championship side Brentford at the Kassam Stadium on Wednesday.
The 23-year-old was given 25 minutes to impress new Us boss Pep Clotet as he replaced Marvin Johnson in the 4-3 defeat.
Hanley was signed last summer by Rob Page, and despite never having played a senior game, he was handed a two-year deal at Sixfields.
The Blackburn-born player made just four substitute appearances for the Cobblers, and none under Edinburgh after he took over as manager in January.
Hanley’s last appearance for Town was as a 77th-minute substitute in the humiliating 1-0 FA Cup defeat at non-League Stourbridge last December.