French coach Raymond Domenech will announce his 23-man World Cup squad on May 11. ((STEPHANE DE SAKUTIN/AFP/Getty Images))

France coach Raymond Domenech is worried that key players like striker Thierry Henry and midfielder Patrick Vieira are out of form less than a month before he announces his World Cup squad.

Henry is struggling to play games for Barcelona, while Vieira has been in and out of the Manchester City team since joining from Inter Milan in January.

"When we have so many injuries and players who are not playing right now, it's not reassuring. If I have to do the (squad) list today, how do I do it?" Domenech said Tuesday. "If the tournament started today we wouldn't be at our best."

Domenech will announce his 23-man World Cup squad on May 11. France goes to its Tignes training camp in the French Alps on May 18.

"There is only one rule: the player who isn't ready on May 18 won't be kept," Domenech said in an interview with sports daily L'Equipe.

France has host South Africa, Uruguay and Mexico in its World Cup group.

Henry and Vieira are the last remaining players from France's 1998 World Cup-winning team. Vieira has made 107 international appearances, while Henry has played 118 times and is the national team's record scorer with 51 goals.

But Henry has started only 14 league games this season and has dropped down the pecking order at Barcelona. He is behind Bojan Krcic and Pedro Rodriguez in attack, where Lionel Messi and Zlatan Ibrahimovic are considered irreplaceable.

'Faith in great players'

Vieira missed City's 5-1 win against Birmingham on Sunday when he pulled out with a sore knee, and the 33-year-old has started only five league games since joining from Inter.

Vieira's form had been somewhat encouraging in the two previous games, with a goal against Burnley and a solid performance in the 3-0 win against Wigan.

Domenech hopes the 32-year-old Henry can force his way back into coach Pep Guardiola's team as Barca looks to defend both its Spanish league and Champions League titles.

"I always have faith in great players and 'Titi' (Henry) is a great player," Domenech said.

Domenech added that there are no guaranteed places in his World Cup squad and warned the players that he is prepared to make ruthless decisions because it's "the team that counts."

Domenech's gamble to take Vieira to the European Championship two years ago backfired, as the veteran failed to shake off a knee injury.

France also has injuries to defenders William Gallas and Eric Abidal, who both played in the 2006 World Cup, where France lost in the final to Italy on penalty kicks.