David Alaba has rejoined Real Madrid group training and is expected to be in the squad for Sunday's La Liga match against Rayo Vallecano, providing a major boost for Xabi Alonso. The defender returns from a calf injury that has seen him miss four games, as the club continues to cope with injuries to Antonio Rudiger, Dani Carvajal and Aurelien Tchouameni.Madrid have received a significant defensive boost as Alaba has rejoined group training and is poised to make his return to the squad for match against Vallecano, according to a report from AS.The 33-year-old defender's return provides a timely solution for manager, whose squad has been severely depleted by injuries, particularly in defence.Alaba participated in the majority of group exercises during Friday's training session at Valdebebas, with the outlook for his recovery described as "very positive." The Austrian international is expected to complete Saturday's final session without issue and be named in Alonso's squad for the trip to Vallecas.The comeback of the experienced centre-back is a critical development for Real Madrid, who are facing an injury crisis in their backline. Alonso remains without four key players for the upcoming league fixture.The injury list includes starting right-back Carvajal and fellow centre-back Rudiger, whose absence has compounded Madrid's defensive woes.Furthermore, the club is without key defensive midfielder Tchouameni, who was the latest player to be sidelined. The Frenchman is suffering from a semitendinosus muscle injury in his left leg and is not expected to reappear until after the upcoming international break. His target is reportedly the match against Elche on November 23. Youngster Franco Mastantuono also remains unavailable.Alaba has been sidelined for Madrid's last four matches after sustaining a strain in his right calf muscle, identified as a soleus injury. The setback occurred at the end of the first half of the club's league match against Getafe on 19 October.His injury, coinciding with Rudiger's spell on the treatment table, forced Alonso to field a makeshift defensive partnership. The manager has had to consolidate a centre-back pairing of Eder Militao and 20-year-old summer signing Dean Huijsen.This pairing was further disrupted during Alaba's absence, with Spanish international Huijsen also missing the Champions League match against Juventus, highlighting the precarious lack of depth Alonso has been navigating.The injury has been a frustrating interruption for Alaba, who has had a limited impact on the 2025-26 campaign. The defender, whose contract expires in 2026, has struggled for consistent fitness and game time.Prior to his injury, the Austrian had featured in only four matches for Madrid this season, accumulating just 145 minutes of playing time.His involvement has been sporadic, receiving minutes from the bench against Real Sociedad and Levante in La Liga, and making one start on the second matchday of the Champions League in Almaty.His return to fitness is therefore crucial not only for the team's immediate needs but also for Alaba himself as he looks to re-establish his role as a cornerstone of the Madrid defence.Provided he passes Saturday's final fitness test, Alaba will be in line for minutes in Sunday's La Liga encounter at Vallecas. Following the match against Rayo Vallecano, Alaba's immediate focus will shift to international duty. The defender has been called up by manager Ralf Rangnick for a potentially huge international break for Austria.The Austrian national team are on the verge of securing qualification for the next World Cup, an achievement they have not managed in 28 years. The country's last appearance at the tournament was in 1998 when it was held in France.Austria will face Cyprus on Saturday, November 15, before a match against Bosnia-Herzegovina the following Tuesday evening. Alaba's return to fitness will be a welcome sight for Rangnick, who will rely on his captain's leadership and experience as his side attempts to make history.