Complex sentence: In December 1986, Feyenoord Rotterdam sent Duut on loan to Fortuna Sittard where he finished the season, after which Fortuna Sittard decided to sign Duut and he played another five years for the club based in Limburg.
Split into simpler sentences: In December 1986 Feyenoord Rotterdam sent Duut on loan to Fortuna Sittard where he finished the season. After that season Fortuna Sittard decided to sign Duut and he played another five years for the club based in Limburg.