After having spent some months playing in Indonesia for Borneo, Lammers returned to the Netherlands, where he signed for Eerste Divisie club TOP Oss on 12 March 2020.[4]
In June 2022, Lammers returned to De Graafschap on a free transfer, signing a two-year contract.[5] After playing regularly for the club, he suffered a back injury which sidelined him the first half of 2024.[6] In June 2024, it was announced that his expiring contract would not be extended, making him a free agent.[7]