 On 13 September 2014, Grimaldo scored his first professional goal, netting his side's last in a 3–2 success at Alavés.In a campaign which saw the team relegated, he netted four times in 36 matches; he and Sergi Palencia were sent off on 25 April 2015, in a 2–1 win over Ponferradina at the Mini Estadi.On 29 December 2015, as his contract was about to expire, Grimaldo signed with Portuguese champions Benfica until 2021, for €1.5 million.