[1] After spending many years of his youth playing with Red Star Belgrade, during which he was loaned to FK Jedinstvo Ub, he decided to accept a challenge that came from Belgium and moved to Lierse S.K.

In spite of arriving to the club off of dry spells in Belgium and Russia, he became Vojvodina's captain after a remarkably short period of time due to a spontaneous explosion of good form.

[4] After seasons spent in Sion, Mrđa returned to the club at which he debuted professionally, signing a two-year contract with Red Star Belgrade.

[10] Mrđa was a part of the Serbian U21 team that made it to the final of the 2007 UEFA European Under-21 Championship, where he scored coming off the bench against the Netherlands U21 side.

[11] In June 2010, he was called up by Radomir Antić to Serbia's squad at the 2010 FIFA World Cup, but didn't make any appearances there.