Great Britain captain Barry Middleton has been rested for this week's test event at the Olympic Park.
The 28-year-old has been left out as coach Jason Lee continues to assess the wider squad prior to this summer's London Games.
Six players - Richard Smith, Dan Fox, Richard Alexander, Nick Catlin, Jonty Clarke and Ali Wilson - who missed December's Champions Trophy in New Zealand are recalled.
"We are still very much in the selection phase ahead of the Olympics this summer," said Lee.
"The final squad for the Olympics will be the best combination of players not necessarily the best individuals.
"When you consider that we have 27 players in the Great Britain squad, all with a chance of Olympic selection, but only 18 players allowed to compete in the test event, then obviously some had to miss out.
"On this occasion, that includes Barry Middleton."
Great Britain's men will face Germany, India and Australia in the tournament.
Squad: J Fair (GK, Cannock); R Alexander, R Moore, J Tindall (Surbiton); N Catlin, J Clarke, I Mackay, S Mantell (Reading); A Dixon, A Wilson (Beeston); D Fox (Hampstead & Westminster); B Hawes (Wimbledon); A Jackson, G Kirkham, I Lewers, M Pearn (E Grinstead); H Martin (Old Loughtonians); R Smith (Loughborough Students).