Alexandre Lacazette has scored 54 times and provided another 25 assists in 153 Premier League appearances for Arsenal
The France forward, 30, is out of contract in the summer and free to speak to other teams.
Arteta said Arsenal took a risk in delaying contract talks with Lacazette.
"The contracts start and end with the expiry date that you have agreed on that day that you put the pen down," added Arteta.
Speaking to Canal Plus earlier in the week, Lacazette said he was "missing" playing in the Champions League and that he had "never cut contact" with Lyon, who he left to join Arsenal five years ago.
Arsenal's hopes of finishing in the top four and qualifying for the Champions League have been dented by three straight defeats before Wednesday's London derby at Chelsea.
The Gunners, who have one game in hand, are three points behind fourth-placed Tottenham with seven matches left.
Lacazette has captained Arsenal since Pierre-Emerick Aubameyang was stripped of the captaincy by Arteta in December for a disciplinary breach.
Aubameyang has since joined Barcelona where he has scored eight times in 10 La Liga games.
Asked about Lacazette's contract situation, Arteta added: "We have expressed clearly what our intention is - to speak in the summer once we know where we are, about what we are going to do in the future together.
"And for the rest, I just want him fully focused on his duty, which is now defend Arsenal in the best possible way, like he has done all the time he has been with us.
"That's why he has been wearing the armband of this football club, that's a big reason."
Lacazette is unlikely to feature at Chelsea after testing positive for coronavirus and Arteta admitted the player's time at Arsenal could be running out, with talks over a new deal having been left until the season is finished.
"It is the agreement that we made with him, that was our position and our position remains the same, that is what we are going to do," he said.
"The risk of that happening, it was always there since the moment we made that decision, then it is up to him."
-- Courtesy of BBC Sport