Question: Which starting centre back was teammates with Lazaros Christodoulopoulos?

Context paragraphs:
Lazaros Fotias: Lazaros Fotias (; born 26 April 1991 in Giannitsa) is a Greek footballer currently playing as a centre back for Slovak club Topvar Topoľčany.

Holger Badstuber: Holger Felix Badstuber (] ; born 13 March 1989) is a German footballer who plays as a centre back for VfB Stuttgart and the German national team.  He is primarily a centre back, although he is a capable left back.  He made his debut in the 2009–10 season in the Bundesliga, at the age of 19, playing nearly every game that year and helped the club win the league and cup double and reached the Champions League final that same year, before eventually earning a call up to the World Cup in 2010.  Former Bayern Munich coach Louis van Gaal stated that he is the best left footed defender in Germany.

Lazaros Christodoulopoulos: Lazaros Christodoulopoulos (Greek: Λάζαρος Χριστοδουλόπουλος ; born 19 December 1986) is a Greek footballer who plays for AEK Athens and the Greek national team.  His main strengths are his technique, pace and acceleration with the ball.  Like his Greek teammate Sokratis Papastathopoulos, his surname is too long to fit on his shirt, so his shirt reads Lazaros instead.

Richard Naylor: Richard Alan Naylor (born 28 February 1977) is an English former footballer who played as a centre back.  Naylor started his career at Ipswich Town, where he played as a striker up until he was moved to centre back by Joe Royle in 2002; he continued to play as a centre back ever since.  He has now retired from professional football and was formerly Under 18's manager of Leeds United, he also included a brief spell as Leeds' Caretaker Assistant manager after the sacking of Neil Warnock in 2013.

Luís Pereira: Luís Edmundo Pereira (born June 21, 1949) is a retired association footballer.  He played centre back, in particular with S.E. Palmeiras, Atlético Madrid and the Brazilian national team.  He won national championships in both Brazil and Spain beyond UEFA and the Intercontinental Cup.  Known for his pace and power, as well as his marking and defensive leadership, he was, for a time, considered one of the best defenders in Europe during his time with Atlético Madrid.  However, he was not as highly regarded in Brazil.  While his defending style can be considered "classical," he is also considered the first and best of Brazil's "modern" centre back, a role that would go on to include world-cup winner Lúcio.

Sokratis Papastathopoulos: Sokratis Papastathopoulos (Greek: Σωκράτης Παπασταθόπουλος , ] ; born 9 June 1988) is a Greek footballer who plays as a starting centre back for German Bundesliga club Borussia Dortmund and the Greek national team.  Since the surname Papastathopoulos is too long to print on the back of most shirts, the name Sokratis is usually displayed and is the singular name that he is best known by in the football world.

Killian Burns: Killian Burns was a Gaelic football player from Sneem Co Kerry.  He played Corner back for Kerry when they won the 1997 & 2000 All-Ireland Senior Football Championships.  He made his debut against Laois in February, 1996.  He won his first Munster Senior Football Championship final for Kerry in 1996 beating Cork 0-14 to 0-11.  Killian scored the last point of the game.  He won an All-Ireland Under-21 Football Championships in 1995 & 1996 beating Mayo and Cavan.  He also won an Hogan Cup in 1992 with St. Brendan's College at corner back, scoring the last point in the final.  He won a National League Division 1 title at corner back beating Cork in the final 3-8 to 1-7 in Pairc Ui Chaoimh.  He won a Munster Junior Championship in 2003 with Kerry at centre back.  Killian played full back for the South Kerry seniors that won the Kerry County Championship in 2004 and 2005 before moving to Dublin side Round Towers.  He currently is playing football with Castlegregory, West Kerry where he currently resides.

Jack Stephens (footballer): Jack Stephens (born 27 January 1994) is an English footballer who plays as a defender for Southampton.  Born in Torpoint, he began his career as a youth player with Plymouth Argyle, remaining with the club as a professional until 2011.  Although starting his career as a right back, Stephens has recently been converted into a centre back.  He can also operate as a left back, or in a defensive midfielder role, and has played internationally for the England under-18, under-19 and under-20 sides.

Anastasios Katsabis: Anastasios Katsabis (born 30 July 1973) is a former Greek football player, who lastly played for Iraklis Thessaloniki F.C. in Greek Super League as a centre back.  Katsabis started his career as a midfielder, but when at PAOK, Angelos Anastasiadis tried him as a centre back because of his height.  It was by playing his new position that he gained his first call-up in the Ethniki.

Ron Vlaar: Ron Peter Vlaar (] ; born 16 February 1985) is a Dutch footballer who plays as a centre back for AZ Alkmaar in the Dutch Eredivisie, having returned to play at his first professional club.  Vlaar is a regular at centre back for the Netherlands national team and has played for and captained both Feyenoord and Aston Villa.

Supporting paragraphs: Lazaros Christodoulopoulos Sokratis Papastathopoulos
Answer: Sokratis Papastathopoulos