How does it work?Thirty-six sides entered into the new "league phase," and now there are 24 remaining. Eight have already gone through to the round of 16, while sides finishing 9th through 24th are headed to the first knockout round — the playoff.

The UEFA Champions League returns Tuesday, Feb. 11 with the first set of knockout stage playoff games. The first legs will wrap up Wednesday, Feb. 12 with the return fixtures taking place a week later.