The Lowdown: David Moyes' High-Flying West Ham United
David Moyes' side have been in stellar form since the turn of the year, recording nine victories from 14 league games in 2021.
The Foxes, meanwhile, are coming into the game off the back of a 2-0 defeat to runaway leaders Manchester City - a first loss in five games - and remain third in the Premier League table, four points in front of Sunday's opponents.
Ahead of the two sides meeting in the capital, LCFC.com takes an in-depth look at the east Londoners...
The squad
Jesse Lingard has proved to be a revelation since his mid-season loan switch from Manchester United, recognised by a return to the England squad in recent games. Since opening his account with two goals on debut at the start of February, the attacking midfielder has registered a total of six goals and four assists in just eight games.
West Ham also have a number of long-serving players including Mark Noble, who has made over 500 appearances for his boyhood side since making his professional debut in 2004, complementing the impressive midfield displays of England international Declan Rice.
Winger Jarrod Bowen, meanwhile, who signed from Hull City in January 2020, started the season off in fine form, netting twice in the home victory over Wolverhampton Wanderers and also against Leicester a week later. With a total of seven goals to his name, as well as three assists, only Michael Antonio (seven goals, five assists) has a higher combined total so far this term.
West Ham made Tomáš Souček's loan move a permanent one last summer, securing the Czech Republic international for a reported fee of £14.5M after the midfielder made 13 appearances during the second half of last season, scoring three goals. And it has proved to be a smart piece of business with Souček weighing in with a further nine goals across this campaign.
In defence, left-back Aaron Cresswell (seven assists) and Italy defender Angelo Ogbonna (two goals) provide experience to the backline and an attacking threat, alongside the likes of Fabián Balbuena and Issa Diop, helping to keep 10 Premier League shutouts - only four teams have registered more this season.
The manager
Former Preston North End, Everton, Manchester United, Real Sociedad and Sunderland manager David Moyes returned to West Ham for a second spell in charge at the end of 2019.
After Manuel Pellegrini left the Hammers, following a 2-1 home defeat by Leicester, the Scottish manager signed an 18-month contract at London Stadium. His first game back in the capital was a 4-0 success over AFC Bournemouth, before another 4-0 win, at Gillingham, in the Emirates FA Cup.
Moyes is an experienced manager who has worked at the game's pinnacle, taking the Manchester United post after 11 successful years at Goodison Park.
He arrived in Merseyside having guided Preston to promotion from the Third Division and settling in the second tier, before sealing Everton a UEFA Champions League qualifying spot in 2004/05.
The Toffees fell in the qualification stages, but finished in the top half for the rest of Moyes' tenure, as well as being beaten FA Cup finalists in 2009, before replacing Sir Alex Ferguson at Old Trafford.
However, Moyes' time at United, which included a Community Shield success, was cut short by disappointing domestic form and the Glasgow-born former defender left the Red Devils in April 2014.
His next move was to Spain to manage La Liga club Real Sociedad in November 2014 and, while form initially improved, Moyes was dismissed a year after taking the post.
Moyes' next job was to replace Sam Allardyce at Sunderland, but his only season in charge at Stadium of Light ended with his first career relegation, as the Black Cats fell into the Championship.
Later that year, his maiden spell at West Ham began in November, with Moyes inspiring the east London outfit to climb out of the relegation zone and towards safety in the 2017/18 campaign.
Despite leaving at the end of that season, West Ham returned to Moyes in late December 2019, to replace Pellegrini as the Hammers aimed to move away from the bottom three.
They finished the 2019/20 season in 16th position, on 39 points, five points clear of the relegation zone.
Form guide
West Ham have enjoyed a fantastic run of form which has moved the club into top four contention. A 3-2 victory over Wolverhampton Wanderers on Monday night got the Hammers back on track after two games without a win.
Jesse Lingard, Pable Fornals and Jarrod Bowen - who also scored in the reverse fixture - all found the net within the first 38 minutes at Molineux, which was enough to take three points back to London, recording a league double over Wolves despite a second-half fightback from the hosts.
Moyes' side were also three goals up at half-time in their last home fixture, against Arsenal, thanks to strikes from Lingard, Bowen and Tomáš Souček, but they were unable to hold on to the lead as the Gunners scored three times without reply to take an unlikely draw from London Stadium.
Nevertheless, West Ham have lost just twice in their last nine league games - both by a single goal against the league's top two clubs, Manchester City and Manchester United.
Previous encounters
Last time the two sides met West Ham triumphed 3-0 at King Power Stadium to inflict a first defeat of the season on Leicester City in October 2020, courtesy of strikes from Michael Antonio, Pablo Fornals and Jarrod Bowen.
The Foxes had the upper hand last season, however, winning both Premier League matches. Leicester won 2-1 at London Stadium in December 2019, before also defeating them in the reverse fixture a month later, with a 4-1 win over the east London side.
In fact, City have lost just two of the last 13 games between the pair. However, of the 135 competitive games, West Ham edge the total number of victories (53) to Leicester's 49. There have been 33 draws, including the first meeting, a Second Division clash back in November 1919, which finished 0-0.
Trophy cabinet
West Ham United have enjoyed success on both the domestic and European front since their formation in 1895.
They have won the FA Cup in 1964, 1975 and 1980, they lifted the Charity Shield (now Community Shield) in 1964 and have won England’s second division on two occasions – in 1958 and 1981.
In 1999, the Hammers won the UEFA Intertoto Cup alongside Juventus and Montpellier, while in 1965, they claimed the European Cup Winners' Cup with a 2-0 success over 1860 Munich.
In front of over 97,000 fans at Wembley Stadium, the late Alan Sealey scored twice in three second-half minutes to win it for his side.
The stadium
West Ham United moved to the London Stadium in 2016, having previously played at Upton Park for over a century.
The 60,000-seater stadium was originally constructed for the 2012 Summer Olympics, serving as a track and field venue.
In addition to athletics and football, the London Stadium has also hosted baseball and rugby league matches, as well as motorsport’s 2015 Race of Champions.
Upcoming fixtures
After hosting the Foxes, West Ham are back on the road to face Newcastle United at St. James' Park on Saturday 17 April (12:30pm kick-off), ahead of meeting Chelsea at London Stadium a week later (5:30pm kick-off).
In May, Moyes' men tackle Burnley (A) and Everton (H) before fixtures against Brighton & Hove Albion (A), West Bromwich Albion (A) and Southampton (H) complete the Hammers' 2020/21 season.
All times BST.