The Swede scored on Saturday against Burnley, but was forced off in the second half and has missed the trip to the Czech capital with his return date yet to be revealed.
The Gunners’ manager admitted the player needed more tests to find out the extent of the problem.
Speaking about Gyokeres, he said: “He’s definitely not available and he hasn’t trained today. He hasn’t had any muscular injuries before. We need to do some tests and scans to understand the extent of the injury.
“I am concerned. He had to leave the pitch as he was feeling something, and that’s obviously not a good sign for a player that is very explosive.”
Leandro Trossard could be the man for the Gunners through the middle on Tuesday, given Gyokeres’ knock. Their striking options are also limited by the long-term absences of Kai Havertz and Gabriel Martinelli.
Speaking ahead of the game, the Belgian remarked about playing up front: “It’s a big change, it also depends on the state of the game and what the manager wants me to do…
“The last couple of years, we have been challenging for the title, we have the same mindset this season as well. We want to win it and we know how hard that is, but I think that we are on the right track, and there is still a long way to go. But, we want to win every game, that’s our mindset.
That sort of mindset will be tested against Slavia Prague. Arsenal have a good record against Tuesday’s opponents, never losing to the Czech side in their four games, winning twice and drawing the others.
Since their last encounter, though, Arsenal are a much-changed side, as Slavia coach Jindrich Trpisovsky noted in his press conference earlier in the day, but Arteta is under no illusions that it will be a difficult game for his players.
Arteta explained: “The team has been competing well in all the competitions, and tomorrow we know that we have a really tough match here. They are unbeaten at home all season, they are a team that are used to playing together, they have a clear philosophy, they create a massive atmosphere, and we know it’s going to be a tough match.”
A trip to Prague also gives the manager a chance to reunite with a former teammate, Sparta Prague director Tomas Rosicky.
Speaking about a potential meet-up, Arteta added: “I will try to see him. We had a great time together (at Arsenal) and I always say that Tomas is one of my favourite players who I played with.
“If there is a chance tomorrow and he is available, we will see each other, give each other a hug and talk a little bit about football.”
Also missing from the trip to the city of a thousand spires is Martin Zubimendi, who is suspended. This could lead to Christian Norgaard getting his first start since moving in the summer.