CREATE TABLE table_68891 ("Team 1" TEXT, "Agg." TEXT, "Team 2" TEXT, "1st leg" TEXT, "2nd leg" TEXT)

What is the second leg that Valencia was on?
SELECT "2nd leg" FROM table_68891 WHERE "Team 2" = 'valencia'
SELECT "2nd leg" FROM "table_68891" WHERE "Team 2" = 'valencia'