Osterc started his career at [[NK Veržej|Veržej]], where he was the top goalscorer of the [[1993–94 Slovenian Second League]] season.<ref>{{cite web |last=Okorn |first=Jože |title=Milan Osterc: Katanec me je zaščitil, ker je trmast |url=https://www.dnevnik.si/1042552057 |website=[[Dnevnik (Slovenia)|Dnevnik]] |accessdateaccess-date=14 October 2020 |language=sl |date=15 September 2012}}</ref> In the [[2001–02 UEFA Cup]], he reached the quarter-finals of the competition with [[Hapoel Tel-Aviv FC|Hapoel Tel Aviv]], scoring seven goals in the process.<ref>{{cite web |author1first=Jaša|last=Lorenčič |title=Manj kot tujec ve, boljše je |url=https://www.vecer.com/201407306047787-6047787 |website=[[Večer (Slovenia)|Večer]] |accessdateaccess-date=28 June 2019 |language=sl-si |date=30 July 2014}}</ref> In the [[2009–10 Slovenian PrvaLiga|2009–10 season]], he was the top scorer of the Slovenian first division, [[Slovenian PrvaLiga|1. SNL]], with 23 goals.<ref>{{cite web |author1first=Toni|last=Gruden |title=Šporar kot kralj strelcev na tujem ob boku Novakovića |url=https://www.rtvslo.si/sport/nogomet/sporar-kot-kralj-strelcev-na-tujem-ob-boku-novakovica/485922 |publisher=[[RTV Slovenija]] |accessdateaccess-date=28 June 2019 |language=sl |date=22 April 2019}}</ref>
==International career==
Osterc played 44 matches for [[Slovenia national football team|Slovenia]]<ref>{{cite web|url=https://www.rsssf.org/miscellaneous/slov-recintlp.html|title=Appearances for Slovenia National Team|access-date=30 December 2023|website=[[RSSSF]]}}</ref> and was a participant at the [[2000 UEFA European Football Championship|Euro 2000]] and the [[2002 FIFA World Cup]]. On 10 November 2001, he scored a goal against [[Romania national football team|Romania]] in the [[2002 FIFA World Cup qualification|2002 FIFA World Cup]] qualifying play-offs, helping to secure his country's first-ever World Cup appearance as an independent country.<ref>{{cite web |title=Osterc dosegel neverjeten gol proti Romuniji |url=https://www.rtvslo.si/sport/na-danasnji-dan/osterc-dosegel-neverjeten-gol-proti-romuniji/109379 |publisher=[[RTV Slovenija]] |accessdateaccess-date=13 October 2020 |language=sl |date=10 November 2012}}</ref> His final international was at that Word Cup, against [[Paraguay national football team|Paraguay]].<ref name="EU"/>
==Career statistics==
===International===
:''Scores and results list Slovenia's goal tally first, score column indicates score after each Osterc goal.''<ref name="EU">{{cite web |title=Milan Osterc, international urlfootball player |url=https://eu-football.info/_player.php?id=15743 | title = Football PLAYER: Milan Osterc | website=eu-football.info |access-date=30 7December October2023 2015|language=en}}</ref>