The left-back has been an unused substitute in Arsenal's last four matches after recovering from a serious hamstring injury, which scuppered his hopes of securing a permanent move elsewhere in the summer transfer window.
Even though Arsenal were missing Oleksandr Zinchenko and Riccardo Calafiori for Sunday's 1-1 Premier League draw with Fulham, Arteta overlooked Tierney again, instead starting Jurrien Timber at left-back and Thomas Partey on the right-hand side.
However, Timber and Partey were both missing from team training on Tuesday, as were Calafiori and Zinchenko, meaning that Arteta may have no choice but to start Tierney or 18-year-old Myles Lewis-Skelly on the left against Monaco.
It is widely accepted that Tierney will leave Arsenal permanently next year, as his style of play no longer fits Arteta's system, but the Spaniard told reporters in his pre-game press conference that the Scotland international is still in the reckoning.
Arteta: 'Tierney deserves opportunities for Arsenal'
"Yeah, he is ready and he's training really well and he's going to have an opportunity for sure with the way the team is looking at the moment," Arteta said.
"It's for that reason and because he's earned it as well with the way he's behaved and the way he's been with us because he's willing to do it and when that happens you have to give opportunities to those kind of players."
As well as Partey and Timber's fresh concerns, Arsenal were missing a potential right-back deputy in training too, as Josh Nichols - who started September's EFL Cup win over Bolton Wanderers - did not take part.
Fellow Under-21s defender Josh Robinson - who has been on the bench three times in Europe this season already - could therefore be in line for a senior debut on Wednesday, but Arteta was typically reserved when asked for a team news update.
"We have to manage a lot of the players, so they're probably not going to be fit for tomorrow and are a doubt. I still have 24 hours to make those decisions and hopefully the right ones," the Spaniard replied.
Will Arsenal let Gabriel Jesus leave in January?
At the other end of the field, Kai Havertz is expected to retain his place up front over Gabriel Jesus, whose run without a goal in the Premier League stretched to 22 games in the stalemate with Fulham.
The Brazilian seemingly pulled out of going for a shot from Declan Rice's ball over the top in the second half, and it has been suggested that he could return to Brazil next month after former club Palmeiras supposedly had an attempt to re-sign him blocked.
However, Arteta firmly shot down such speculation when asked on Tuesday, replying: "No, no sense," before giving Jesus a public vote of confidence, adding: "Like all strikers, they go on phases and moments and that gap is becoming big.
"It's true that obviously a lot of things has happened, injuries, absences of not playing or starting games that much but his attitude has been really good, it always is, and we're going to try to help him overcome the situation as soon as possible."
Arsenal and Monaco are only separated on goal difference in the top eight of the Champions League table, but they could drop out of the automatic last-16 qualification spots depending on the results of Tuesday's matches.
Written by
Ben Knapton