Neymar & Coutinho lead Brazilian charge
Brazil is the only country to appear in every World Cup and the only nation to win the trophy five times. After losing at home in the final match in 1950 they won back-to-back titles in 1958 and 1962 and then made it three in Mexico in 1970 with what many consider to be the greatest team of all time. After a 24-year drought that included heart-breaking eliminations in 1982 and 1986 they won again in 1994 with Romario and Bebeto starring. A rejuvenated Ronaldo, back from a series of knee injuries, helped them win the title in Japan in 2002 but they have disappointed since, not least in losing 7-1 to Germany in the semi-final at home four years ago.
Coach: Tite
Key players:
Neymar: So much of Brazil's hopes rest on Neymar's slim shoulders. The greatest player of his generation is capable of winning any game with a moment of brilliance but he will be returning from three months out with a foot injury and it remains to be seen whether the rest is positive or negative. He coasted through his debut season at Paris St-Germain where he was rarely tested.
Philippe Coutinho: This has been a rollercoaster season for Coutinho, who started at Liverpool and ended up at Barcelona. The 25-year-old has nevertheless become a regular in Tite's side, in either a wide role or as a deeper lying central midfielder, and his long-range shooting is a powerful weapon.
Paulinho: With a superb defence and a scintillating attack, Brazil's midfield is often overlooked. Paulinho is a key cog in Brazil's engine room and a trusted lieutenant of coach Tite, who oversaw his rise at Corinthians. When he is on form Paulinho is an old-style box-to-box midfielder, but the Barcelona player is notorious for blowing hot and cold.
Form guide:
Brazil's form going to Russia could hardly be bettered. Since Tite took over as coach in mid-2016 they have lost once in 19 games, in a friendly against Argentina in Australia. The key to their form is at the back. They have conceded just five goals in those 19 games.
Prospects:
This tournament is an unusual one for Brazil, who will arrive as joint favourites and as a side that need to prove themselves all over again after their disastrous 7-1 loss to Germany in the 2014 semi-finals. They should sail through Group E against Switzerland, Costa Rica and Serbia but, with little experience playing competitively against top European sides, a question mark still exists. One mouth-watering prospect could come as early as the last 16. If Brazil or Germany qualify in second place from their groups, the two heavyweights will slug it out much earlier than they would like.
Costa Rica hope to replicate 2014 performance
Costa Rica will be appearing in their fifth World Cup four years after their best finish with a run to the quarter-finals in Brazil, where they lost to the Netherlands on penalties.
Few expected Costa Rica to get out of a group featuring three former World Cup winners -- England, Italy and Uruguay. However, some spirited and enterprising displays saw the Central Americans top the section and beat Greece on penalties in the last 16 before their heartbreaking defeat by the Dutch.
The first appearance of Los Ticos in a finals was at Italia '90 where they upset the odds by beating Scotland and Sweden to qualify from their group but then lost 4-1 to Czechoslovakia.
In 2002 and 2006 they failed to get out of their group.
Coach: Oscar Ramirez
Key players:
Keylor Navas: The 2014 World Cup changed the goalkeeper's career when, after a series of outstanding performances, particularly against Greece in the last 16, he was signed by Real Madrid to replace Iker Casillas.
Bryan Ruiz: The main creative force for Los Ticos, Ruiz has played in Europe since 2006 and the 32-year-old is enjoying something of an Indian summer at Sporting in Portugal.
Joel Campbell: The 25-year-old striker's career has yet to live up to the expectations generated by his move as a teenager to Arsenal. But while his club career has consisted of a series of loan moves to Spanish clubs, Campbell has shown his quality for Costa Rica.
Form guide:
Since qualification was secured, Ramirez's side have suffered three defeats in four friendly games with a solitary win against Scotland. Defeats by Tunisia and Hungary hardly inspired confidence, while a 5-0 thrashing by Spain set off alarm bells. Ramirez will be hoping for better signs in June's friendlies against Northern Ireland, England and Belgium.
Prospects:
Serbia, Brazil and Switzerland represent a tough challenge in Group E. Costa Rica's performances in advancing from an arguably tougher group four years ago offers hope but they do not look as sharp or effective as Jorge Luis Pinto's 2014 side.
Recent form would suggest Costa Rica will need a huge improvement to have any chance of getting out of the group.
Swiss bank on strong qualifier form
Switzerland have appeared at 10 World Cups, reaching the quarter-finals in 1934, 1938 and again in 1954 when they hosted the tournament. They missed six tournaments in a row from 1970 to 1990 inclusive. They did not concede a goal in the 2006 tournament, when they lost to Ukraine on penalties in the second round, failing to convert any of their spot kicks in a 3-0 shootout defeat.
Coach: Vladimir Petkovic
Key players:
Xherdan Shaqiri: His impish skills make him Switzerland's most entertaining and dangerous player. The 26-year-old packs a powerful left-foot shot and can also unlock defences with cunning, incisive passes.
Scored a hat-trick against Honduras at the last World Cup and his bicycle-kick goal against Poland in Euro 2016 was arguably the most spectacular ever scored by a Switzerland player at a major tournament.
Granit Xhaka: Playing just in front of the defence, the left-footed Xhaka dictates the pace in midfield with his cool, measured passing and also offers a physical presence and is a strong tackler.
Nevertheless, he divides opinion and is often made the scapegoat for the failings of his club side Arsenal. Sent off 11 times in his career, he also has a volatile streak.
Stephan Lichtsteiner: The team captain and right-back is known as "Forrest Gump" for his energetic running down the flank and his eight goals in 98 internationals are an indication of his impressive attacking prowess.
Form guide:
Switzerland have lost only one match, away to Portugal in the World Cup qualifiers, since Euro 2016. They beat Greece 1-0 and Panama 6-0 in their two March friendlies.
However, apart from Portugal, they have been untested against top-level opponents in nearly two years.
Prospects:
With Brazil expected to win Group E comfortably, Switzerland are likely to be locked in a three-way battle with Costa Rica and Serbia for second place.
The Swiss probably would not have chosen to begin against Brazil. They then face Serbia and round out group play against Costa Rica, who reached the quarter-finals four years ago.
If they manage to finish second they will face the winners of Group F -- probably Germany -- in the last 16.
Serbia remain underdogs
Serbia featured in one previous tournament as an independent nation, the 2010 World Cup when they made a group-stage exit after a shock win over Germany and defeats by Ghana and Australia. As part of the Serbia and Montenegro state union, the team made a group-stage exit in the 2006 tournament and they reached the last 16 as part of the Federal Republic of Yugoslavia (also consisting of Serbia and Montenegro) in the 1998 World Cup.
Coach: Mladen Krstajic
Key players:
Nemanja Matic: The Manchester United enforcer pulls the strings in midfield and is expected to protect the back four as well as orchestrate the attacks. His versatility and consistency will be key to Serbia's hopes of advancing into the knockout stages.
Dusan Tadic: The Southampton winger was instrumental in the first half of the qualifying campaign, having been involved in 11 of Serbia's 12 goals (four goals and seven assists) in the opening five games. Tadic has plenty of pace, a bag of tricks and is a decent finisher, making him one of the team's most reliable forwards.
Aleksandar Mitrovic: The Newcastle United striker was Serbia's top scorer in qualifying with six goals and has been in good club form recently after moving to Fulham on loan in January. The 23-year-old is a robust, old-fashioned striker, always a handful for his markers in the penalty box with two good feet and aerial power.
Form Guide:
Serbia enjoyed a consistent qualifying campaign with six wins, three draws and one defeat under Muslin, followed by two wins, a draw and a defeat in warm-ups under Krstajic. The Serbians scored in every 2018 qualifier and averaged two goals per game.
Prospects:
Serbia's chances of advancing to the knockout stages of the tournament are likely to rest on the opening two games against Costa Rica and Switzerland, as they will be underdogs in their final group match against Brazil, winners of a record five World Cups.
There is plenty of potential in an experienced side including only three survivors from the 2010World Cup squad and how the young players cope with the pressure will be vital.
