McDonald has been among the most consistent forwards in Gaelic football for the last ten years.[when?] He is known for his playmaking role and his exemplary passing. He is considered one of the best exponents of the difficult skill of kicking the ball with the outside of the boot.
McDonald made his inter-county début in the Under-16 Ted Webb Cup in 1990 at the age of 15. His first Championship for the Mayo senior team was 1994. He came on and scored as a substitute in the final of the Connacht Senior Football Championship. However, that game ended Mayo's involvement that year in what was an historic season for Leitrim.
Deciding to spend the summer abroad, McDonald missed the eventful 1996 season, when Mayo lost the 1996 All-Ireland Senior Football Championship Final against Meath in a replay. He returned in 1997 when Mayo again lost in Final, though McDonald scored a second-half penalty in the game. In 1998 Mayo were knocked out by arch-rivals Galway early in the Championship, though McDonald scored two goals in that game and famously hit the crossbar very late in the game when looking for a third goal which would have turned the game in Mayo's favour. Galway went on to win the Championship that year.
McDonald is held in high regard in County Mayo and seen as one of the best forwards Mayo has ever produced.