Wales lock Ben Carter's tour to Japan lasted all of 27 seconds as he was released from the squad on Tuesday after suffering a concussion in Saturday's first test defeat.
Carter, 24, was involved in a heavy collision immediately at the start of the clash in Kitakyushu and underwent several minutes of treatment on the field before being carried off on a stretcher.
The Welsh Rugby Union said on Tuesday he would take no further part in the tour and head home on Wednesday.
Wales lost 24-19, after being 19-7 up at halftime, extending their record losing streak to 18 matches.
The two teams meet again on Saturday in the second test at Misaki Park in Kobe.