Career
In 1960 he moves to NK Maribor. During the 1960s he became one of the most proeminent Slovenian players. He was part of Maribor team that got the promotion to the Yugoslav First League in 1967.
He played with Maribor until 1969, making 58 appearances and scoring 15 goals in the top tier during the last two seasons there. was interested in bringing as well Tomislav Prosen and Mladen Kranjc, who, along Arnejčič, were the main players of Maribor, however at the end they only brought Arnejčič in a deal which meant that Milan Janković, Vladislav Bogićević and Rade Radić moved to Maribor.
After winning both national titles with in only one season, Arnejčič failed to impress, and he moved abroad in summer 1970 by joining Austrian Nationalliga (predecessor of Bundesliga) side Grazer Alaska. He made 12 league appearances and scored 4 goals in the 1970-1971 Austrian football championship in which GAK finished in 11th place. In summer 1971 Milan Arnejčič returned to his home-town club NK Maribor, still playing in the Yugoslav First League, although in the first season he returned, 1971-1972, they finished bottom of the league and were relegated to the Yugoslav Second League.
Despite those events, Milan Arnejčič kept playing with NK Maribor all the way until 1978, when he retired. In total he spent 16 season with Maribor playing 286 matches and scoring 73 goals.