Kostas Tsimikas will wear the No.21 shirt for Liverpool.
The Greece international left-back completed his transfer to the Reds from Olympiacos on Monday.
And he has selected the vacant No.21 jersey, which was most recently worn by Alex Oxlade-Chamberlain, at his new club.
“I like it as a number. I took it in Holland when I played there, then the next year in Olympiacos and I wore it for two years and now here,” the 24-year-old explained to Liverpoolfc.com during his first interview as a Reds player.