Question: What was the first season as manager of the current manager of Premier League club West Ham United?

Context paragraphs:
Slaven Bilić: Slaven Bilić (; born 11 September 1968) is a retired Croatian professional footballer and current manager of Premier League club West Ham United.

Freddie Sears: Frederick David "Freddie" Sears (born 27 November 1989) is an English professional footballer who plays as a forward for Ipswich Town.  He started his career with his local club West Ham United at the age of eleven, progressing through the West Ham United Academy.  He made a scoring first-team debut in March 2008 when he netted the winner against Blackburn Rovers after coming on as a second-half substitute.  Sears made over 50 first-team appearances for West Ham, but never held down a regular starting position.

West Ham United F.C. managers: London football team, West Ham United have had only fifteen permanent managers in their history and an additional three caretaker managers.  Up until 1989 the club had only had five different managers.  Before the appointment of Gianfranco Zola in 2008 the club never had an overseas manager, with the only non-Englishman being the Scot, Lou Macari.  The current manager is Slaven Bilić who was appointed in June 2015.  The most recent manager before that was Sam Allardyce who was appointed in May 2011 and left the club in May 2015.  Numerous former West Ham players have taken on temporary managerial roles at the club, between permanent managers.  Ronnie Boyce briefly took the reins, in February 1990, between Macari's resignation and the appointment of Billy Bonds.  Former Hammer's player and board member Trevor Brooking was briefly in charge during two separate spells as caretaker manager in 2003, first during the illness of Glenn Roeder and again between Roeder's sacking and the appointment of Alan Pardew.  Former player Kevin Keen has been caretaker manager twice; immediately prior to Gianfranco Zola's appointment in 2008 and after the sacking of Avram Grant in 2011.

Toni Martínez: Antonio Martínez López (born 30 June 1997), commonly referred to as Toni Martínez, is a Spanish professional footballer who plays as a forward for Premier League club West Ham United.  He has represented Spain at under-17 and under-19 level.  Prior to joining West Ham, Martínez played for Real Murcia and Valencia at under-19 youth level.

2012–13 FC Lokomotiv Moscow season: The 2012–13 Lokomotiv Moscow season involved the club competing in the Russian Premier League and Russian Cup.  It was Slaven Bilić's first season as manager and ended with the worst league result of the team (9th, the lower part of the table) since establishing of Russian Championship in 1992.  As a result, the contract of Bilić was terminated by mutual agreement on 17 June 2013.

West Ham United F.C. Under-23s: West Ham United F.C. Under-23s, formerly West Ham United F.C. Under-21s is the most senior of West Ham United's youth teams.  The Under-23 team is effectively West Ham United's second-string side, but is limited to three outfield players and one goalkeeper over the age of 23 per game following the introduction of new regulations from the 2012–13 season.  They play in Premier League 2 and also compete in the Checkatrade Trophy.

Reece Oxford: Reece Joel Oxford (born 16 December 1998) is an English professional footballer who plays as a defender for Borussia Mönchengladbach on loan from Premier League club West Ham United.  Oxford made his debut for West Ham aged 16 years and 198 days, making him the club's youngest ever player, beating a record of 16 years and 221 days set in 1922 by Billy Williams.

Pablo Barrera: Pablo Edson Barrera Acosta (born 21 June 1987) is a Mexican footballer who plays as a winger or outside forward for Liga MX club UNAM.  He spent the early part of his career playing for Club Universidad Nacional in Mexico, before transferring to Premier League club West Ham United.  He has also spent a loan period with La Liga club Real Zaragoza.  He has represented the Mexico national team.

West Ham United F.C. Reserves: The West Ham United Academy is recognised as one of the most successful academies in modern football, hence its nickname the Academy of Football.  The introduction of the FA's new Academy system in 1998 has placed even more emphasis on the developing of young homegrown players and today the youth system at West Ham is more important than it has ever been.  With the influx of many foreign players in the Premier League during modern times, West Ham United has been regarded as one of the few remaining clubs in top flight to continue producing and playing homegrown English players.

Sam Byram: Samuel Mark "Sam" Byram (born 16 September 1993) is an English professional footballer who plays for Premier League club West Ham United.  He primarily plays as a right back, but can also play as a right midfielder or right winger.

Supporting paragraphs: 2012–13 FC Lokomotiv Moscow season Slaven Bilić
Answer: 2012–13 Lokomotiv Moscow