Valábik scored his first career OHL goal on November 7, 2003, against Josh Disher of the Erie Otters in an 8–1 win.

He finished the 2003–04 season with 3 goals and 16 points in 68 games, as well as accumulating 118 penalty minutes, helping the Rangers make the playoffs.

In the post-season, Valábik was held pointless in five games as Kitchener were eliminated by the Plymouth Whalers in the Western Conference quarter-finals.

In 15 playoff games, Valábik was held off the scoresheet, as the Rangers eventually lost to the London Knights in the Western Conference finals.

In the playoffs, Valábik recorded two assists in five games as the club lost to the Owen Sound Attack in the Western Conference quarter-finals.

He played in his first career AHL game on October 7, 2006, also registering his first point (an assist), in a 5–0 win over the Peoria Rivermen.

In his next game, on October 13, Valábik scored his first career AHL goal, against Karl Goehring of the Milwaukee Admirals in a 7–5 victory.

He finished the season playing in 50 games with Chicago, scoring 2 goals and 9 points, helping the Wolves clinch a playoff spot.

On April 26, 2008, Valábik scored his first career AHL playoff goal, against Pekka Rinne of the Milwaukee Admirals in a 3–0 victory.

Overall, Valábik appeared in 24 playoff games with Chicago, scoring 3 goals and 4 points as the Wolves ultimately won the Calder Cup.

Valábik returned to the lineup on November 20, 2009, and would play in six games with Chicago, earning no points, before being called up to Atlanta again.

He appeared in one playoff game, being held off the scoresheet, while earning 17 penalty minutes, as the Pirates lost to the Syracuse Crunch in the Eastern Conference quarter-finals.