Career
Vojvodina
Katai started playing football for his hometown club FK Vojvodina youth squad. After 6 months loan to lower league team FK Palić at the start of 2009-2010 season he was promoted to Vojvodina"s first team He"s debut in Serbian SuperLiga was on 14 March 2010, when he came in as substitute against FK Čukarički, and he scored his first goal just seven days latter in a match against FK Mladi Radnik.
On June 28, 2011, he left FK Vojvodina and went to Athens to join Olympiacos.
Olympiacos
On June 24, 2011, Olympiacos agreed to sign Katai on a four-year contract. However, as an Olympiacos player, Katai did not play a single match for Olympiacos, but was instead sent on loan four times.
He was first loaned to OFI Crete, with whom he made his debut on November 5, 2011, against Panionios. The loan spell to Crete was unsuccessful, and so Olympiacos loaned him back to his hometown club FK Vojvodina.
While on loan at Vojvodina, in 2012 after one game with Spartak Subotica, he felt very ill and went to the hospital, where he was diagnosed with thrombopenia.
He had to have some blood removed and stayed in the hospital for two weeks before he was allowed to recover from home. During his recovery, he had gained over 20 pounds, and did not return to play football until the end of the year. He remained a loaned player for Vojvodina until the club president Ratko Butorović died unexpectedly on June 8, 2013, which led to a period of instability in the club during which Katai left.
He subsequently was loaned to Platanias, for whom he scored a total of eight goals and six assists until his loan there expired in the summer of 2014.
Red Star Belgrade
On August 31, 2014, in a last-minute deal before the transfer window closed, Katai devoted to a one-year loan to Red Star Belgrade. Throughout the fall of 2014, Katai was reported to be out of shape, and Red Star"s coach Nenad Lalatović was said to have claimed that Katai "had a problem in his head".
On June 18, 2015, it was announced that Katai terminated his contract with Olympiacos and forgave a debt of €300,000 which was owed to him by Red Star from the loan contract, and subsequently signed a two-year contract with Red Star Belgrade. Foreign the 2015-2016 season, Miodrag Grof Božović was hired as the new coach and Katai played good game against Kairat in first qualifying round for the Europa League, although Red Star failed to qualify.
By the end of October 2015, Katai had scored 10 goals and recorded 6 assists in 15 league matches, ranking him as one of the most effective midfielders in all of Europe at the time surveyed.
Katai played two games for Serbia U21 national team On October 5, 2015, Katai received his first senior call-up to make an international debut against Albania and Portugal in Union of European Football Associations Euro 2016 qualifying.