The Argentine teenager, who joined the club from River Plate in August 2025, has been sidelined since early November after the injury flared up ahead of the Champions League trip to Liverpool and the subsequent La Liga match against Rayo Vallecano.
Mastantuono had quickly established himself as one of the breakout stars under Xabi Alonso, often deployed on the right flank or drifting inside as an attacking midfielder, where his direct running, vision, and left-footed creativity added a new dimension to Madrid's attack.
The issue, the same pubalgia that has troubled young explosive wingers like Barcelona's Lamine Yamal and Athletic Club's Nico Williams this season, has proven tricky to manage, with both Spanish internationals experiencing recurring setbacks after attempted comebacks.
Club medical staff initially feared a lengthy absence, but conservative treatment involving physiotherapy, core-strengthening exercises, dry needling, and shockwave therapy has been preferred over surgery.
As of mid-November 2025, sources indicate the teenager is progressing steadily during the international break, building lower-body strength after adding muscle mass since arriving in Madrid. However, Real Madrid have refrained from public timelines, mindful of how rushed returns aggravated similar cases for Yamal and Williams.
In Mastantuono's absence, Alonso has experimented with several options on the right. Eduardo Camavinga provided energy and impressed in parts during El Clasico, but appeared less suited to the wide role at Anfield and against Rayo.
Jude Bellingham and Arda Guler have also been trialled there, though neither is a natural wide player, Guler in particular has looked more effective centrally, where his tendency to cut inside onto his stronger left foot is better utilised.
Madrid's last match of 2025 is at home to Sevilla on 21 December, before the brief winter break. While there is quiet optimism internally that Mastantuono could be in contention sometime in the festive period if his response continues positively, the priority remains avoiding any relapse. His potential return would give Alonso a much-needed natural option on the flanks heading into a congested January schedule.
