Manchester United boss Sir Alex Ferguson says Javier Hernandez was admitted to hospital after a training ground mishap.
Doctors initially favoured keeping Hernandez in for observation until Friday but agreed to let him leave on Wednesday after seeing the results of scans.
Hernandez rested at the team hotel while United beat the Major League Soccer All-Stars 4-0 at Red Bull Arena and has been cleared to travel when they fly to Washington DC on Thursday ahead of their final tour game against Barcelona.
He will not be allowed to play for a fortnight, although Ferguson doubted whether Hernandez would have featured in that time anyway as he is eased back to fitness after a long season which ended with Mexico's participation in the Gold Cup and a brief holiday.
"He is back in the hotel," said Ferguson, after United beat the All-Stars. "He is in his room and will be out for a couple of weeks.
"He would never have been available for Barcelona anyway because he has just come back from his break after the Gold Cup.
"He will travel with us though, he's okay for that. He got concussion in training and we dealt with that. We took him to hospital, he had a scan, it was all clear."