HARRISON, N.J. -- United States defender Fabian Johnson has been sent home so that "he can rethink his approach about his team," coach Jurgen Klinsmann said on Monday.
Klinsmann was unhappy that Johnson removed himself in extra time of Saturday's 3-2 defeat to Mexico in the CONCACAF Cup.
Johnson came off in the 111th minute with the score level at 2-2, only for Paul Aguilar to score the winner seven minutes later.
Klinsmann replaced him with Brad Evans, but the coach said on Monday that Johnson was not hurt.
Johnson -- who was beaten by Javier "Chicharito" Hernandez on Mexico's 10th-minute opener -- had complained of muscle tightness before being pulled.
"I had a very severe word with Fabian Johnson, and I sent him home today," Klinsmann said. "He can rethink his approach about his team.
The tightness Johnson felt was not related to the right hamstring injury that sidelined Johnson for five weeks in August and September, a U.S. soccer spokesman confirmed.
"He said he couldn't go anymore and I reacted to it and obviously and made the substitution," Klinsmann said. "He just feared to possibly get an injury, but he was not injured in that moment. He got all stiffened up. It's a muscle issue. It's normal."
Had the U.S. and Mexico gone to penalty kicks, the substitution would have prevented Klinsmann from replacing starting goalkeeper Brad Guzan with shootout specialist Nick Rimando, as planned.
"In a situation like that," Klinsmann said, "it's little things that often make a difference."
Johnson will not play for the U.S. against Costa Rica in Tuesday's friendly at Red Bull Arena (7 p.m. ET, ESPN). The 27 year-old, who plays for Borussia Monchengladbach in Germany, is the only U.S. player to feature in the UEFA Champions League this season.
Tuesday's match is the Americans' final tune-up before qualifying for the 2018 World Cup in Russia begins next month with a pair of games -- in St. Louis against St. Vincent and The Grenadines on Nov. 13 and four days later at Trinidad and Tobago.