Jose Enrique has returned to pre-season training with Newcastle, but his agent has not ruled out him leaving St James' Park this summer.
The left-back has been heavily linked with a move away from Tyneside, with just a year left to run on his current Toon contract.
Liverpool are thought to have a long-standing interest in his services, while Arsenal are likely to require a replacement for Gael Clichy if he completes a switch to Manchester City.
Newcastle are yet to receive an offer for the 25-year-old Spaniard, but his agent Salvador Sanchez has refused to confirm if he will remain with the Magpies.
"He is back at Newcastle now, and he is going to start pre-season with them," Sanchez told talkSPORT.
"We just have to wait and see what happens.
"Our policy is not to make any comments about the situation, though."
Enrique arrived at the club in 2007 from Primera Liga side Villarreal and has gone on to establish himself as a key player.
The defender, who previously spent time at Valencia, has notched up 119 appearances during his spell at St James' Park.
Meanwhile, Newcastle have confirmed they will face Serie A side Fiorentina in their final pre-season friendly.
The Magpies will take on Sinisa Mihajlovic's men at St James' Park on Saturday, August 6th (kick-off 3pm).
Fiorentina, who boast former Celtic keeper Artur Boruc and Italy striker Alberto Gilardino among their ranks, finished ninth in the league last season.
It will be the first time the two sides have met since the final of the 1972-73 Anglo-Italian Cup in Florence, a game Newcastle won 2-1.