The forward is believed to be have been a target for the club back in January before they landed Mbwana Samatta from Genk.
Back then, the player’s agent Theofilos Karasavvidis said a fee in the region of £20million would represent a bargain for the 23-year-old who has scored 29 times this season.
Now, though, Rangers are reported to want £35million for the player who – as well as being prolific with goals – is also no stranger to a booking.
Morelos has been sent off seven times over the course of the last two seasons and has picked up 29 yellow cards during that spell.
But his goals mean he is likely to move on when the transfer window reopens with the likes of Atletico Madrid, Inter Milan and Sevilla also credited with an interest.