Taylor (left) was knocked out by Arthur Abraham in October
American boxer Jermain Taylor has withdrawn from the Super Six super-middleweight tournament, which also involves Britain's Carl Froch.
The 31-year-old, a former undisputed world middleweight champion, was knocked out by Germany's Arthur Abraham on his Super Six debut in October.
The decision by Taylor, who was also knocked out by Froch in April, leaves an uneven five men in the tournament.
"It's important I give my body and mind some much-needed rest," said Taylor.
"I plan on keeping myself in shape and making a return to the sport some time in the future.
"This was not an easy decision for me, having discussed it with my family, trainer, friends and my adviser Al Haymon, because I'm a very competitive person. But I know this is the smart road for me to take."
Taylor was knocked out with seconds to go against both Froch - when he was ahead on two judges' scorecards - and Abraham.
Promoter Lou DiBella severed ties with Taylor before Christmas, but Taylor said he still intended to fight fellow American Andre Ward, who defeated Denmark's WBA super-middleweight champion in the Super Six in November.
However, his change of heart is not a surprise, and it leaves the tournament's organisers, American television network Showtime, with a headache.
Taylor was scheduled to fight Ward in April and Showtime had previously said contestants would be replaced if one of the six dropped out, although it was not immediately clear who was first in line.
Nottingham's WBC title-holder Froch outpointed Andre Dirrell in his Super Six opener and next faces Kessler in Denmark in April.