 Later that year in another match between the two teams, Collymore went in with a two-footed challenge on Harkness's standing leg in the ninth minute of the match, causing him to be substituted with injury.Harkness left Anfield to join up with old manager Graeme Souness at Benfica on 9 March 1999 for £750,000.He was one of several British players signed for the Lisbon club by Souness, and chose to wear only his first name on the back of his shirt there.