The 22-year-old joined Los Rojiblancos on loan from River Plate at the start of the campaign and has established himself as a key performer in Gregorio Manzano's side.
Atletico have the option to seal a permanent ‚é¼6 million (£4 million) deal for the South American stopper when his loan spell finishes on June 30, but now fear his eye-catching performances might lead to rival interest in him.
The capital club are desperate to retain Lequi's services, and have already arranged talks with the player's agent Paco Casal to negotiate his client's next contract.
The Argentine Under-20 international has made 18 appearances this term and has forged a solid central defensive pairing with Jose Antonio Garcia Calvo.
Atletico originally moved for the ex-Rosario Central man after seeing their bid to sign his compatriot Gabriel Milito - now at Zaragoza - fall through last summer.
