Career
Wulnikowski began with football in his hometown at the Polish club Zawisza Bydgoszcz. In 1990, he entered the youth division of the Football Club Schalke 04. In 1997, he was promoted to the second team of the club and played in the Oberliga Westfalen.
In 1999, he joined the third division team 1.
Football Club Union Berlin. At Union Berlin, Wulnikowski was initially substitute goalkeeper behind Kay Wehner (Saison 1999–2000) and Sven Beuckert (2000–2002). In 2001, Union was promoted to the 2.
Bundesliga without Wulnikowski playing a single league match. In the 2000-2001 DFB-Pokal quarter-final against VfL Bochum, Wulnikowski came on after 30 minutes for an injured Beuckert.
After the dismissal of longtime coach Georgi Vasilev in October 2002 and the commitment of coach Mirko Votava, Wulnikowski became first-choice goalkeeper Foreign Union Berlin.
By the end of the 2003-2004 season, after the club was relegated as next to last in the table again, Wulnikowski had completed a total of 54 second-division games for the club Wulnikowski moved then to Rot-Weiss Essen for an unknown transfer fee. At the beginning of the season, Wulnikowski was in the starting squad, but made an error in the first match.
From matchday three on, coach Jürgen Gelsdorf replaced him with René Renno.
At the end of the season, Rot-Weiss Essen was relegated and the contract with the goalkeeper cancelled. In 2005, Wulnikowski subsequently joined VfR Aalen in the Regionalliga Südaughter
He completed two seasons as first-choice goalkeeper there. In April 2007, Wulnikowski announce his move to league rivals Sportfreunde Siegen.
During the 2007-2008 season, he was first-choice goalkeeper for Siegen.
At the beginning of the 2008-2009 season, he moved to the third division club Kickers Offenbach. In the 2009-2010 winter break, he extended his contract for another three years until the end of the 2012-2013 season. On 27 October 2010, he became nationwide famous for his fantastic match in the 2010-2011 DFB-Pokal against Borussia Dortmund, in which he saved two penalties and single-handedly destroyed Dortmund"s several other good goal chances.
He left Offenbach at the end of the 2012-2013 season, after they were relegated from the 3.
Liga. After six months without a club, he signed for RB Leipzig II for half a season, before joining Würzburger Kickers in July 2014.