The 27-year-old has not played a single minute for Mikel Arteta's side this season, having spent months recovering from the severe hamstring injury he sustained while playing for Scotland at Euro 2024, but he has been on the bench for their last four matches.
There is seemingly a good chance that Tierney will make his first appearance of the campaign against Monaco in Wednesday's Champions League clash, as Arteta is grappling with a defensive injury crisis and extended an olive branch to the defender in his pre-game press conference.
However, Watts has affirmed that Tierney's long-term future belongs away from the Emirates, and the club will look to shift him out temporarily over the winter before trying to find a buyer in the summer of 2025.
Asked if there was a future for Tierney in North London, Watts said: "There's not, there's not. It's an absolute nailed on, if he's fit, January departure for Kieran Tierney. A loan until the end of the season, go out and get some minutes and try and leave on a permanent basis in the summer.
"There is no future for Kieran Tierney at Arsenal. Everyone gets that and understands that. It's very, very clear. Had he not been injured at the Euros, I'm sure he would have gone in the summer. That was the hope that he'd have good, strong Euros, he'd put himself in the shop window, but the fact is he is here now. January isn't here yet and Arsenal need a left back. So use him.
'If you need Kieran Tierney, use Kieran Tierney'
"Maybe there's a fear that if he got injured, that would scrap the January move, I don't know if that's playing into their minds a little bit, but needs must really. He's paid to play for Arsenal at the moment. He's an Arsenal player. So if he's there and you need him, then use him, surely."
Tierney immediately cemented himself as a fan favourite in North London following his arrival from Celtic in 2019, when Unai Emery was at the helm, but he has been hampered by injuries and does not possess the qualities Arteta is looking for in his left-backs today.
The Scotland international thrives on the overlap, whereas the defenders ahead of him in the pecking order - Riccardo Calafiori, Oleksandr Zinchenko, Jurrien Timber, Takehiro Tomiyasu and, to an extent, Myles Lewis-Skelly - are superior at inverting into the central areas.
However, Timber and Lewis-Skelly could be Arsenal's only left-back options for the showdown with Monaco, as Tomiyasu is definitely out with a knee injury, while Zinchenko, Timber and Calafiori all missed training on Tuesday and are doubtful for the contest.
Speaking before it was revealed that Timber was uncertain anyway, Watts implored Arteta to wrap the Dutchman in cotton wool and place his faith in either Lewis-Skelly or Tierney, the latter of whom would "not let anyone down" if given a chance.
"Timber needs a rest at some point because if something was to happen to Timber, Arsenal would be absolutely screwed," Watts added. "He's playing all the time at the moment because Tomiyasu is injured, because Ben White's injured, there's just no other option apart from Thomas Partey at right back.
'Old-school Tierney would not let anyone down'
"At some point, Timber's going to need a rest and I was looking at this game as potentially the chance to give him a rest ahead of Everton, but if all the issues with the defenders who are currently out, none of them come back, I think Timber's going to have to play, unfortunately.
"I would like to see him play another player at left back, definitely. Lewis-Skelly, Arteta's shown he's trusted him. He's thrown him on at the Etihad in the 2-2. Kieran Tierney's a top, top player, a proper international defender who was so crucial to the early stages of the Arteta era at Arsenal. Most of us at the time who were watching that week in, week out, just presumed he'd go on and be Arsenal captain one day. It seemed certain.
"The system and the way Arsenal play have changed and that's left Tierney behind, that old-school left-back type player who's not really what Arsenal look for in a left back anymore, but he's still a very good player. He's been on the bench for the last four games now, he's been training for a long time. If he's fit, he would not let anyone down playing in these games.
"If he's a squad member, you've got him on the bench, I don't see why you don't use him. We're not talking about an inexperienced player here, we're talking about Kieran Tierney, a £25m defender. If he's fit, I'd just play Kieran Tierney. It just feels so simplistic to me and just the easy, sensible option."
Tierney has not taken to the pitch for Arteta's side since the 2023 Community Shield win over Manchester City, having spent the majority of last season on loan at Real Sociedad before picking up his injury at the Euros.
The Scotsman has registered five goals and 13 assists in 124 appearances for Arsenal, who have him under contract until 2026, and Watts also discussed the future of misfiring striker Gabriel Jesus after the Brazilian's latest fruitless cameo in Sunday's 1-1 Premier League draw with Fulham.
Written by
Ben Knapton