In the following years, Van der Kuijlen faced a few struggles in his career. His Philips job and a call up for the military draft proved difficult to combine with his football. In both the 1966-67 and the 1967-68 season, Van der Kuijlen still produced 21 league goals but a lack of chemistry between him and PSV coach Milan Nikolić also made his performances suffer. In 1968, PSV was struggling in the league and battling relegation. As a result, Nikolić was sacked and in the wake of his departure, Van der Kuijlen immediately scored four goals in a 5-1 victory against DWS. After a few important wins, PSV ended 14th in the Eredivisie. In the 1968-69 season PSV appointed Kurt Linder as the new coach. But once again, Van der Kuijlen did not get along with his coach, having trouble with Linder's harsh coaching style. This situation almost led to a transfer by Van der Kuijlen to Helmond Sport, his hometown side. They could not afford his transfer fee though, and Van der Kuijlen ultimately signed a new contract with PSV.