He played as a forward for Willem II Tilburg, RKC Waalwijk, VVV-Venlo, Toulon, NAC Breda, RBC Roosendaal and New Zealand club Auckland Kingz.

He was subsequently signed by SBV Excelsior as Alex Pastoor's aide at the small Rotterdam-based club.

[1] After one year to serve as head coach, he left Excelsior in charge of Eerste Divisie club FC Eindhoven.

[4] On 25 June 2022, Heracles Almelo appointed Lammers as head coach on a two-year deal with an option for another year, after the club had suffered relegation to the second-tier Eerste Divisie.

[5] On 26 March 2024, Lammers was announced as VVV-Venlo's new head coach ahead of the 2024–25 season, replacing the outgoing Rick Kruys who had decided to seek new challenges.