The Colombian striker, whose current deal at the DW expires at the end of the season, has failed to agree new terms.
"We don't have the money which other clubs have got to invest, but the benefit is that we don't have to sell players either," Martinez told reporters.
"And it is much more important to keep Hugo playing for us until the end of the season than trying to cash in on him right now. We want him to concentrate on his football and getting back to his best.
"Then we will have to see where we are at the end of the season."
Rodallega has scored just the one goal for the Latics this season.