In the 1972–73 preliminary round, the young striker played ten games with four goals for Osnabrück and then moved to Den Bosch for the 1972–73 Eredivisie.

[1] Den Bosch, who were in the penultimate place in the Eredivisie when Graul arrived, were unable to improve until the end of the season and were relegated.

He scored eleven goals in 16 games and thus played a significant role in Arminia's 14th place in the table and the associated nomination for the inaugural 1974–75 2.

Bundesliga, compared to the last round of the Regionalliga and, under coach Erhard Ahmann, finished fourth in the Nord Division with 50:26 points behind champions Hannover 96, runners-up Bayer 05 Uerdingen and FC St. Pauli.

Volker Graul became the second league top scorer with 30 goals ahead of Gerd-Volker Schock, who would later play quite successfully for Arminia.Arminia benefited from new signing Ewald Lienen, who overran the opposing defensive lines from the wing and also shone with good assists to the centre-forward after his dribbles.

Since Bielefeld prevented Graul from the possibility of transferring to either Bayern Munich or to Hamburger SV, now with little motivation, scored only eleven goals in 24 appearances in the 1975–76 2.

[1][2] Münster came in sixth place in the 1976–77 season with the coaches Rudi Faßnacht and Werner Biskup from April 1977, equal on points with several other teams.

In the cathedral city, he increased his scoring rate to 18 goals, but Fortuna only reached fourth place under coaches Ernst-Günter Habig and from January 1978, Rudi Faßnacht which prevented the long-awaited return to the Bundesliga.

In the 2–0 victory, the attack was manned by Reiner Geye, Karl-Heinz Handschuh, Graul, Bernd Gersdorff and Josef Pirrung.

In the 1983–84 Oberliga Westfalen [de], he was involved in the FC Gütersloh affair together with Roland Peitsch and successfully sued for his promised "salary" in a total amount of 180,000 DM in a civil court, whereupon the Westphalian Football and Athletics Association sentenced him to a fine of 15,000 marks and a three-year ban for violating amateur regulations.

[4] Graul retired as a footballer at the age of 30 out of annoyance as in the following three years he more or less only played in the Borgholzhausen old men's team of TuS Solbad Ravensberg and ran a trade in used cars.

[5] In 2006, Graul, together with player agent Fali Ramadani, played a central role in the embezzlement investigations against the ex-manager of Bayer 04 Leverkusen, Reiner Calmund, in which the family of Burim Osmani [de] are also said to have been involved.

During his career as a player, he was often compared to his teammate Ewald Lienen due to both being from the same state of North Rhine-Westphalia as it would experience a boom in football throughout the 1970s and 1980s.

This was due to their contrasting perspectives in their careers, whereas Lienen refused to sign autographs and was a critic of capitalism, Graul would often have no qualms with it.