ESPN's journalist Rodra broke the news that Real Madrid have contacted Hincapie's representatives to assess his situation, having already strengthened their defence with the free-transfer signing of Ibrahima Konaté from Liverpool.
Mourinho's interest in the 24-year-old Ecuadorian stems from his versatility — Hincapie is capable of playing as a central defender or at left-back — and his left-footed profile, which is understood to be a specific requirement for the position the Madrid manager wants to fill.
The timing is complicated by Arsenal having only just completed Hincapie's permanent signing after activating the mandatory purchase clause in his season-long loan from Bayer Leverkusen, with the total deal exceeding €50m. Fabrizio Romano confirmed in May that a five-year contract had already been agreed between player and club.
Hincapie started 39 matches for Arsenal across all competitions last season, contributing to a Premier League title triumph and appearances in both the Carabao Cup final and the Champions League final against Paris Saint-Germain.
Any Real Madrid move for the defender would depend on departures. The club are understood to be open to offers for central defender Raúl Asencio and are listening to bids. Further recruitment in defence or midfield is expected to hinge on sales being concluded first.
Barcelona had also been linked with Hincapie before Madrid's interest emerged.