Question: What position did Cristian Dario Alvarez play for the Spanish football team based in Zaragoza?

Context paragraphs:
Deportivo Aragón: Real Zaragoza Deportivo Aragón is the reserve team of Real Zaragoza, a Spanish football club based in Zaragoza, in the autonomous community of Aragon.  Founded as an independent club in 1964, currently plays in Segunda División B – Group 3, holding home matches at "Ciudad Deportiva del Real Zaragoza", with a capacity of 1,000 seats.

RSD Santa Isabel: Real Sociedad Deportiva Santa Isabel is a Spanish football team based in Zaragoza, in the autonomous community of Aragón.  Founded in 1970, it plays in Regional Preferente de Aragón, holding home games at "César Lainez", with a 1,000-seat capacity.

2011–12 Real Valladolid season: The 2011–12 Spanish football season is Real Valladolid's second season in the second level in Spanish football after being defeated 3–2 on aggregate against Elche in La Liga promotion play-off in June 2011.  This season will be the 31st of Real Valladolid in the second level in Spanish football.  The general coordinator during last season, Chuti Molina, left his work on 14 June, becoming Real Murcia general director.  On 17 June, Real Valladolid made official Abel Resino's detachment as he did not renew his contract as team manager.  On 4 July, Carlos Suárez announced he had bought 59% of the club shareholding, becoming shareholder of Real Valladolid, and therefore the owner of the entity.  At the same time he confirmed that he will not step down as chairman and, from the next day, news about the sporting aspect will be known.  Earlier on 6 July, the club became official the incorporation of the Serbian manager Miroslav Đukić for the next 3 seasons.  During that day, it also was confirmed that José Antonio García Calvo, general director, left his work. <br>Real Valladolid qualified in 3rd position in Segunda División, behind both Deportivo and Celta de Vigo, with 82 points.  It was the first time in the history that any team with 80+ points wasn't directly promoted to La Liga.  Deportivo de La Coruña beat Real Valladolid's points record, getting 91 points in the whole season.  The record was established by José Luis Mendilibar's team in 2007 when Real Valladolid scored 88 points and were champions. <br>The team had to play the Promotion play-off again, and got the promotion to 2012–13 La Liga by winning 3–0 on aggregate to Córdoba in the Semifinal and by 2–1 to AD Alcorcón in the Final.

Cristian Darío Álvarez: Cristian Darío Álvarez (born 13 November 1985) is an Argentine professional footballer who plays for Spanish club Real Zaragoza as a goalkeeper.

Zaragoza CD: Real Zaragoza Club Deportivo and later simply Zaragoza Club Deportivo was a Spanish football club based in Zaragoza, founded in 1925 as result of the merger of Athletic Stadium (founded on 1919) and Zaragoza FC (founded on 1921).  The club played its games at Campo de la Torre de Bruil, on 1932 merged with Iberia SC to form the current Real Zaragoza.

Real Zaragoza: Real Zaragoza, S.A.D. (] ) is a Spanish football team based in Zaragoza, in the autonomous community of Aragon.  Founded on 18 March 1932 it currently plays in Segunda División, holding home games at "La Romareda", which seats 34,596 spectators.

CB Zaragoza: Club Baloncesto Zaragoza is a basketball team based in Zaragoza, Aragón, who played from 1981 to 1996 in the top Spanish league (Liga ACB since 1983) and nowadays plays in the 1ª División, the fifth tier.  Most of the years in which the team played in Liga ACB, CB Zaragoza was also known as CAI Zaragoza for sponsorship reasons.

Iberia SC: Iberia Sport Club was a Spanish football club based in Zaragoza, Aragon.  The club was founded in 1916, and played its games at Estadio Torrero, on 1932 merged with Zaragoza Club Deportivo to form the current Real Zaragoza.

CD Valdefierro: Club Deportivo Valdefierro is a Spanish football team based in Zaragoza in the community of Aragon.  Founded in 1960, it plays in 3ª – Group 17.

CD Giner Torrero: Club Deportivo Giner Torrero is a Spanish football team based in Zaragoza in the community of Aragon.  Founded in 1967, it plays in Regional Preferente.

Supporting paragraphs: Cristian Darío Álvarez Real Zaragoza
Answer: as a goalkeeper.