FRANKFURT, Jan 23 (Reuters) - Germany coach Juergen Klinsmann called up 28 established players on Monday for fitness tests at the end of January and said others had until May to force their way into his World Cup plans.
The same 28-man squad called up for the last round of tests in October will join Klinsmann to have their progress monitored again from January 30-31 in Duesseldorf.
Klinsmann expects to choose his 23-man squad for the World Cup from those players but says he would be happy for someone else to come through and make his life a bit more difficult.
'The door will stay open until mid-May, in case a striker knocks in 10 or 15 goals,' the coach said in an interview with Kicker magazine on Monday.
'Surprises are still possible.'
Hosts Germany get the World Cup underway with a Group A match against Costa Rica in Munich on June 9. The final is on July 9 in Berlin.
Before the finals, Germany have friendly matches against Italy, the United States, Japan and Colombia.
German squad for fitness tests in Duesseldorf, January 30-31:
Goalkeepers: Oliver Kahn (Bayern Munich), Jens Lehmann (Arsenal, England), Timo Hildebrand (VfB Stuttgart)
Defenders: Arne Friedrich (Hertha Berlin), Andreas Hinkel (VfB Stuttgart), Robert Huth (Chelsea, England), Marcell Jansen (Borussia Moenchengladbach), Philipp Lahm (Bayern Munich), Per Mertesacker (Hanover 96), Christoph Metzelder (Borussia Dortmund), Patrick Owomoyela (Werder Bremen), Lukas Sinkiewicz (Cologne), Christian Woerns (Borussia Dortmund)
Midfielders: Michael Ballack (Bayern Munich), Sebastian Deisler (Bayern Munich), Bastian Schweinsteiger (Bayern Munich), Tim Borowski (Werder Bremen), Torsten Frings (Werder Bremen), Fabian Ernst (Schalke 04), Thomas Hitzlsperger (VfB Stuttgart), Sebastian Kehl (Borussia Dortmund), Bernd Schneider (Bayer Leverkusen)
Forwards: Gerald Asamoah (Schalke 04), Kevin Kuranyi (Schalke 04), Mike Hanke (VfL Wolfsburg), Miroslav Klose (Werder Bremen), Oliver Neuville (Borussia Moenchengladbach), Lukas Podolski (Cologne)