Arsenal are open to Oleksandr Zinchenko leaving the club amid interest from Atletico Madrid, but his exit would mean Kieran Tierney staying until the summer.

Following initial reports suggesting a potential move to Borussia Dortmund, Arsenal defender Oleksandr Zinchenko has been increasingly linked with Atletico Madrid in recent days.
David Ornstein tells NBC Sports that Arsenal are open to Zinchenko leaving, but it would mean that they’d shut the door on a move for Kieran Tierney.
“We’ve got the possibility of Oleksandr Zinchenko departing Arsenal, they would be open to that,” Ornstein confirmed. “If he goes, it means that Kieran Tierney would be staying.
“He’s had interest in him from clubs taking him on loan for January, Tierney, even though Arsenal will be letting him go for nothing in the summer. He’s expected to move to Celtic.”

Recent reports suggest Tierney is on the verge of agreeing a pre-contract with Celtic, turning down opportunities to pursue a move abroad or to stay in the Premier League.
There were reportedly a whole host of clubs interested in signing Tierney on a free transfer this summer, reportedly including Bayer Leverkusen, Sevilla, and Juventus. In the Premier League, Everton also showed an interest.
But there’s been some talk that once Celtic agree terms with Tierney, they could then make an effort to bring the deal forward to the January transfer window. That might be possible if Zinchenko stays, but evidently not if he goes.

Tierney has made five appearances for Arsenal this season, returning from a serious hamstring injury in late November. He’s been a regular off the bench recently, appearing as a substitute in four of the last five in all competitions.
Mikel Arteta clearly sees value in Tierney as a squad player, so he’s not one Arsenal are desperately looking to cast out this month.