The Swiss Football Association (SFV) has confirmed that veteran forwards Alexander Frei and Marco Streller have retired from international duty.
"Alex Frei, aged 32, and Marco Streller, aged 30, both players from FC Basel, have announced their immediate resignation from the national team to coach Ottmar Hitzfeld," read an SFV statement.
The association attributed the players' decision to negative comments from supporters. "The criticism has taken an amplitude above what is acceptable, and has sometimes infringed on the private sphere of the two players," it stated.
"They realised that in such an atmosphere, it would not be possible to reach the optimal performance level during matches with the national team. This realisation finally pushed them to resign from the national team, before the EURO qualifying match on 4 June 2011 in England."
Frei, who had been Switzerland's captain, is his country's all-time scorer with 42 goals in 84 appearances.
Streller, meanwhile, has 37 caps and 12 goals to his name.