 In late January 2017, Rubén was loaned to Belgian club R.S.C.Anderlecht as Davy Roef moved in the opposite direction in a similar move.He made his debut on 16 February, keeping a clean sheet in a 2–0 home win against FC Zenit Saint Petersburg for the round-of-32 of the UEFA Europa League, which was also his first ever appearance in European competition.