Substitute

заме́стник

zaméstnik

(replacement or stand-in)

замести́тел

zamestítel

(replacement or stand-in)

смя́на

smjána

(player who is available to replace another)

заме́ствам

zaméstvam

(to use in place of something else)

сме́ням

sménjam

(to use X in place of Y)

сме́ням

sménjam

(sports: to remove from the field and bring on another player)