Stewart Downing apologised to Middlesbrough fans after their 4-0 thrashing at Bournemouth.
They were 2-0 down after 16 minutes and played for 70 minutes with 10 men after Gaston Ramirez was sent off.
The Teessiders are nine points off safety with five matches left and could be relegated as early as next Sunday.
"We can only blame ourselves and nobody else. It's hard to take," said former England player Downing.
"Sorry to the fans, they've travelled a long way. They've been first class all season."