Celtic and Rangers have been linked with moves for English Premier League defenders.
Both teams are in the market for defensive reinforcements with Neil Lennon on the lookout for a right-back and centre-back, while Steven Gerrard is also keen on a centre-back and possibly a left-back.
With Mikael Lustig confirming his departure via an Instagram post it leaves Anthony Ralston as the club's only right-back.
The club had been linked with a move for Sheffield United's George Baldock. But, according to the Scottish Sun, attention switched to ex-Celtic full-back Adam Matthews and Arsenal's Carl Jenkinson.
The latter is ready to leave the Gunners with West Brom interested in the one-time England international.
Arsenal are reportedly considering using the player as a makeweight in a deal to bring Kieran Tierney to the Emirates.
The star left-back has attracted interest from a number of big names, Napoli the latest to express an interest.
Meanwhile, former Everton and England defender Phil Jagielka was spotted in Glasgow on Wednesday with ex-Rangers director of football Gordon Smith.
It fuelled speculation that the 36-year-old could be joining Rangers or Celtic.
However, it is understood neither club are interested in the veteran defender with the player a friend of Smith's son.
Jagielka has played more than 350 games in the Premier League.