In 27 La Liga games he has scored 12 goals and provided 10 assists - helping them into fourth in the table, a Champions League spot.
It has been a more than productive return for the Mexican, who spent as much time away from Arsenal on loan as he did at the Emirates as he failed to make the breakthrough and become a regular.
Arsenal were recently linked with bringing him back - they have a buy-back clause of 4.2 million Euros available to them.
Except Vela does not want to go back to the Gunners; at the end of last month he said: "I've never regretted signing for Real and the results prove me right.
"I'm talking about giving more, not just this season, but over the coming years. I think the team can improve even more. We can do better than we are now."
And then this week he added: "I have never demanded respect, I just want to do my work, not mess with anyone and just enjoy playing every weekend.
"I am happy, they are giving me love and trust and letting me play as I know. They give me my freedom and things are going well, with the team also."
It is quite simple. Sociedad want to cancel the buy-back option in Vela's contract.
How they go about this, and what Arsenal would get in return is another issue, but all they can do is talk to the Gunners and see what they have to say.
Sociedad have heard the rumours regarding the fact Arsenal could be interested, but say they have had no contact to date, and clearly want to get it sorted out.
AS report that the Spaniards want to 'enjoy' having Vela over the rest of his contract without having the 'obstacle' of Arsenal's buy-back clause hanging over them.
It seems fair, but then many will say they should not have agreed to it in the first place.
One point to consider is that Arsenal were this week linked with Vela's seven goal teammate Antoine Griezman, a 21-year-old French winger. If Arsenal stump up the money to try and sign him, perhaps they will cancel the buy-back clause to try and reduce the fee.
What do you think Arsenal should do regarding Vela and his buy-back clause?
image: © wonker