Srečko, with Croatian roots, started playing football at the age of 7 at NK Ljubljana. In 1981 he went to Olimpija Ljubljana, in 1985 to Dinamo Zagreb and next year to Partizan Belgrade and was a Yugoslav champion in 1987. In 1988 he joined VfB Stuttgart. This team reached UEFA Cup finals in 1989 and lost against Diego Maradona's Napoli. He stayed in Germany only one season. In 1989 he signed for Italian Sampdoria and already at his first season there he won European Cup Winners' Cup. In 1991 his Sampdoria won a "scudetto", next year it reached Champions League finals and lost against FC Barcelona. In 1994 Sampdoria also won Italian Super Cup.
He was already selected into Yugoslav national team at 1984 European Championship in France, but he has fonder memories of 1984 Olympics in Los Angeles where Yugoslavia team won a bronze medal. He was playing successfully in the qualifying round for 1990 World Cup in Italy so he became the third Slovenian to play at a World Cup where he played 3 matches of 5. Those were the last three caps for Yugoslavia, in altogether 31 matches he scored 5 goals.
Then he played 5 more matches (and scored 1 goal) for Slovenian national team but only one official match. That was a qualifying round for the 1996 European Championship in England, it took place on September 7 1994 in Maribor against Italy. Soon after this match his contract with Sampdoria expired and he finished his football playing career.
Since 1996 he co-coached Slovenian U-21 team with Drago Kostajnšek. Meanwhile he successfully finished a school for trainers and in 1998 he became a coach of HIT Gorica. But not for a long time as on July 1 of that year he was chosen a Slovenian national team selector.
He led his team very successfully through the qualifying round and managed to qualify to the 2000 European Championship in Belgium and the Netherlands and thus started a football mania in Slovenia. There Slovenia played well, it played draw against FR Yugoslavia and Norway and lost against Spain which was considered quite successful. Slovenia also managed to qualify to the 2002 World Cup in Japan and South Korea but this time the team played worse, lost all three matches against Spain, Republic of South Africa and Paraguay, but the most disappointing was Katanec's huge argument with team's first star Zlatko Zahovič. Because of this he resigned immediately after the World Cup and on November 2 in the same year he was chosen a coach at Olympiakos Pireaus. It is believed that his argument with Zahovič played a crucial role as the club also had arguments with Zahovič 3 years before. But under Katanec's command Olympiakos played worse than expected and on February 7 2003 the club's management took a chance and fired him immediately after his criticism of the relations inside the club.
In 2004 he was a serious candidate to become a national team coach of Croatia with a support of Croatian Football Federation. But a lobby of influential coaches and managers strongly opposed him so Srečko decided to quit the candidate procedure and Zlatko Kranjčar was chosen instead of him.