He made his debut for the club on 16 July 2009, starting in a 1–0 away win against NK Rudar Velenje, for the season's UEFA Europa League.

[2] He made his debut in the competition on 29 August, coming on as a second-half substitute in a 0–0 home draw against UD Almería;[3] he scored his first goal on 23 January of the following year, in a 2–3 away loss against the same team.

On 13 January 2012, Lekić scored a first-half goal in a 1–2 home loss against FC Barcelona for the campaign's Copa del Rey.

On 11 November 2015, Lekić signed a deal with Indian club Atlético de Kolkata midway through the second ISL season.

Lekić made his debut for Serbia in a November 2009 friendly match away against Northern Ireland, coming on as a 76th-minute substitute for Danko Lazović, and earned a total of 10 caps (no goals).