 Remanining in Chile, Graff then helped Coquimbo Unido promote from the Primera B to the Primera División in 2018.The following season, he led the team to the fifth place with the subsequent qualification for the first stage of the Copa Sudamericana.In December 2019, even though he had renewed his contract shortly after, Graff signed a two-year deal with O'Higgins and was officially presented late in the month, being received at the Monasterio Celeste by 16 fans (in reference to the Tomé Tragedy) and the board of directors.