The 22-year-old has made two league appearances for Boro from the bench since arriving from Argentine club Banfield this summer.
Payero was brought on with five minutes remaining, plus 10 minutes of stoppage-time, as the Teessiders were beaten 3-2 by QPR at the Riverside.
When asked by the Mail how far away the player is from being ready to start in the league, Warnock replied: “At the moment he’s quite away.
“We just have to try and give him minutes when we can. I just thought it was worth shoving him on and he might have just unlocked the door.
“They were obviously sitting deep and taking five minutes every goal kick so we thought it might just be something just to change it.”
Payero was booked for a late foul against QPR and, despite his technical ability, Warnock says the player has to make adjustments to his game.
“We haven’t seen an awful lot with the games, we’ve had so many games,” replied the Boro boss when asked about the impression Payero has made in training
“He has technical ability, there is no doubt about that. It’s just the pace of the game we have to get him up to.
“You saw that with the free-kick, it was a silly free-kick, a lazy free-kick. He has to know a bit more about the Championship.”
Boro will now prepare for this weekend’s trip to Derby.