With 16 goals for Lyon this season, the forward has enjoyed a fine start to life in Ligue 1 following his move from Real Madrid last summer.
The Dominican Republic-born striker is content in the French top tier for the moment but has plans to return to Spain before he decides to hang up his boots.
“I am very happy in Lyon but one day in the future I would like to return to Spain,” Mariano told Cadena Cope.
“It was the correct decision by Madrid to let me go… for me, for them, for Lyon. But it is true that it would be a dream for me to return in the future.”
Uwe Rosler was sacked by Fleetwood following a 3-0 reverse at Doncaster which condemned Town to a seventh straight defeat in all competitions.
Cambridge interim head coach Joe Dunne was pleased with how his side adapted to beat Grimsby 3-1.