I can't find any information about when Saka will be able to return to the game, but it looks like he has a serious injury, at least Arteta was upset when he said it. But it looks like Arsenal are playing well without him, Saka has been out since the end of December and Arsenal have played a lot of important games during this time, it looks like they have learned to play without him, and of course his return will strengthen Arsenal's attack, because he created a lot of scoring chances.
Even though Saka has now started to train again, it is not certain that he will return to playing with Arsenal in the near future. Because what I know is that Saka has a hamstring injury, so with the injury that Saka has suffered, I think the time he can play again at Arsenal might not be in the near future. Because I saw information regarding when Saka could return to playing again, and the contents of the information said that it was estimated that Saka would be able to return to playing at Arsenal on April 1. This means that if the information is correct it will take another 6 weeks for Arsenal to be able to play Saka again.
But as we know, even without Saka, Arsenal's performance is fine. It is proven that currently Arsenal is still firmly in second place in the English league. So even though it's still a long time before Saka can return to Arsenal, this won't be a problem for Arsenal. Because Arteta as Arsenal coach has been able to restore Arsenal's performance after Saka was injured. So even without Saka Arsenal would be fine. But it is true, if Saka can return to playing with Arsenal, of course Arsenal will have an even better composition of players. But I'm sure that even though Saka can play again, maybe Saka needs more time to return to his best performance.