England manager Roy Hodgson has warned Mark Noble he "cannot cap everyone who is having a good season" and compared the calls for his selection to those for Grant Holt to be picked before the last World Cup.
The West Ham captain has enjoyed a fine campaign, with Slaven Bilic's side in the hunt for a surprise top-four finish as well as making the FA Cup last eight, where they will host Manchester United in a replay.
But uncapped Noble, 28, was not called up for England's friendly double-header against Germany and Netherlands in a severe blow to his hopes of making Euro 2016.
Danny Drinkwater of Leicester City was selected for the first time, but Hodgson insisted it is hard for new players to force their way into a squad that is performing well and compared Noble's situation to that of journeyman striker Holt, now at League One side Rochdale.
"I can only repeat what I have said all along," said Hodgson. "There is always a player or two or three that are in the news with many people thinking they should have been selected or are better than the ones I have selected.
"There is only space for 20 outfield players and I can't unfortunately cap every player who is having a good season. Before the World Cup it was Grant Holt so there is always someone.
"I refuse to close doors and I refuse to rule people out. Having said that, there are a lot of players over last two years who have worked really hard and established themselves as England players.
"Those on the outside still looking to get in have really got to convince me that I am better off leaving out one of the players I am working with to make space for them."
England play Germany in Berlin on Saturday before they welcome Netherlands to Wembley next Tuesday.