Ronaldo is tied to a long-term contract at Real Madrid, but admits he cannot say where his long-term future will lie.
The Portugal international intends to see out a deal which is due to run until 2015, but is then expected to make a move elsewhere.
A return to Old Trafford has been touted for a man offloaded by United in 2009 for a world record fee, with Ronaldo himself admitting to having strong emotional ties to the Red Devils.
Sir Alex Ferguson claims he would welcome the prolific frontman back with open arms, with Ronaldo the kind of player who would improve any side.
That would appear to suggest that United would be in the running were Ronaldo to become available, but for now Gill is keen to play down the rumours and focus on a meeting between United and their former fans' favourite in the last 16 of the UEFA Champions League.
He told Sky Sports News HD: "He is a brilliant player but he is contracted for the next two-and-a-half years at Madrid.
"We are looking forward to welcoming him back, he will get a great reception at Old Trafford in early March and that is all we have got to say."