In 1998–99, Rachůnek improved his offensive numbers to 3 goals and 12 points in 39 games, as well as accumulating 88 penalty minutes, helping Zlín reach the playoffs.

In 62 games with the Griffins, Rachůnek had 6 goals and 26 points, helping Grand Rapids earn a playoff berth.

He earned his first NHL point on November 11, 2000, an assist on a goal by Magnus Arvedson in the Senators' 4–3 loss to the Philadelphia Flyers.

He would score his first NHL goal on January 16, 2001, on Los Angeles Kings goaltender Jamie Storr in a 7–6 loss.

Rachunek missed the first part of the 2002–03 season due to a contract dispute, as he played for Lokomotiv Yaroslavl of the Russian Superleague.

Rachůnek also played in six games with the Binghamton Senators of the American Hockey League (AHL), earning two assists.

His time with the Senators came to an end as of March 9, 2004, after he was traded alongside Alexandre Giroux to the New York Rangers in exchange for Greg de Vries.

He scored his first goal and point as a Ranger on March 25, 2004, beating goaltender Tomáš Vokoun of the Nashville Predators in a 4–2 loss.

With the 2004–05 NHL lockout cancelling the season, Rachůnek signed with Orli Znojmo of the Czech Extraliga on September 6, 2004.

On November 15, 2004, Rachůnek returned to Lokomotiv Yaroslav of the RSL, where he first played during the 2002–03 season when he and the Ottawa Senators could not agree to a contract.

On August 31, 2008, Rachůnek signed a contract with HC Dynamo Moscow of the Kontinental Hockey League (KHL).

Rachůnek returned to Dynamo Moscow for the 2009–10 season, where he scored 10 goals and 27 points in 52 games, helping the club reach the post-season.

At the 1999 World Junior Ice Hockey Championships held in Winnipeg, Rachůnek scored one goal and four points in six games as the Czech Republic finished in seventh place.

At the 2009 IIHF World Championship in Switzerland, Rachunek had four assists in seven games as the Czech Republic finished in sixth place.

At the 2011 IIHF World Championship in Slovakia, Rachůnek had a goal and three points in nine games, helping the Czech Republic to the bronze medal.

"[6] It was during the takeoff, after the runway of 3 kilometres, that the airplane simply could not get up high enough, according to reports the plane reached a total altitude of 10–50 metres before hitting a pylon and dropping to the left.