Mikel Arteta said Max Dowman is "ready" to start if needed after ruling Bukayo Saka out of Sunday's clash with Manchester City.
Saka has not featured since last month's Carabao Cup final and Arteta has confirmed he will not be available at the Etihad Stadium for a game described as a "final" by Pep Guardiola.
Arsenal's lead over Manchester City was cut to six points after last weekend's defeat to Bournemouth and they face their title rivals, live on Your Site, having played a game more.
Arteta hopes to have Noni Madueke available despite the winger suffering an apparent knee injury in Wednesday's meeting with Sporting but insists he won't hesitate to use 16-year-old Dowman.
Dowman has impressed across 11 senior appearances this season and became the youngest scorer in Premier League history with his goal against Everton in March, aged 16 years and 73 days.
"He will be ready, I am sure," said Arteta at his press conference.
"You throw him into any context, this kid, and you know what he will be delivering.
"He has shown that this season in whatever games we have used him."
Dowman was Madueke's 63rd-minute replacement in the Champions League quarter-final second leg against Sporting and the England international was seen limping afterwards.
"We have another training session tomorrow and it didn't look too bad after the game," added Arteta.
"He is quite positive, and he is a player who pushes through pain.
"I am hopeful he can be available but we will see if he is able to train."
The continued absence of Saka is a blow, regardless. Like captain Martin Odegaard, another injury doubt to face City, and the fit-again Kai Havertz, he has endured an injury-hit campaign.
"He is just starting to do some stuff," said Arteta. "Let's see that progression and how quickly we can go through. At the moment, he is not available."
Arteta rejected suggestions that Arsenal could play for a draw at the Etihad Stadium, insisting he is preparing his team to win and reopen their nine-point lead.
"It is certainly the most important game, as it is the next one," he said when asked if he views the game as the biggest of his Arsenal tenure.
"We have earned the right to be in this position, to be challenging. With the possibility to win on Sunday, arguably against the best team and manager that this league has ever seen.
"That is a huge privilege. We cannot wait to play the game and we are going to prepare to win. We see it as a big opportunity for us.
"We are not going to spend one second about that [playing for a draw]. We prepare every game to win and that is why we are where we are. We will do the same.
"Our team has to give every tool to go and win it. We have a strong opponent in front us. We know what we have to do."
Meanwhile, Pep Guardiola accepted Manchester City's Premier League title bid will be finished if they lose to Arsenal in Sunday's crunch clash between the top two teams.
The Spaniard added that while an Arsenal win at the Etihad Stadium this weekend would end City's title challenge, there could still be plenty of twists and turns ahead with half a dozen games left to play.
"Obviously, if we lose it's over," Guardiola said. "But there are still games to play. The reality is there are seven games left for us in the Premier League and that is the decisive moment.
"Maybe they are not at their best, but they are the only English team in the Champions League and they have been the best so far. We want to challenge them.
"I said today to the players, it is just a football game and we have to approach it like a football game. If you get distracted by emotions, that is how you lose focus.
"The target is to perform well and that is exactly what you have got to do and all the aspects required to challenge a team like Arsenal. The confidence is good, we are ready."
Ruben Dias continues to miss out for City and while there were doubts over Nico O'Reilly, who hobbled off at Stamford Bridge with a hamstring problem, Guardiola revealed the in-form full-back will be available.
Arsenal, seeking their first top-flight crown since the 2003-04 season, have been dogged this season by accusations of pragmatism over excitement and relying on their skill at set-pieces.
"People are so demanding," Guardiola said. "From the media, supporters, everyone. I enjoy watching them. I learn a lot in many things. People what they want is to win and we'll fight.
"An aspect that is really, really important that we cannot fight against is 22 years without winning the Premier League. They have something that makes them unique.
"I knew that feeling when we arrived here. I know how you feel that first win. That is something that we cannot play against. That's why we have to focus on the way we have to play."
City, who have lost just one of their 15 league matches at home this season, ended Arsenal's quadruple bid four weeks ago as O'Reilly's double sealed a 2-0 win in the Carabao Cup final at Wembley.
Guardiola, though, is expecting his opposite number and former assistant at City, Arteta, to make some alterations.
"If we play like we did for 95 minutes and they do what they did, we are going to win," Guardiola added. "But I know Mikel a little, they are going to adjust something and we have to be prepared.
"Every year they are getting better and better. Last season, Liverpool were incredible but the previous one and this season, Arsenal have been the biggest contender."
