Marrow joined Crystal Palace on loan until January at the start of the season and the versatile 20-year-old has impressed in nine appearances for the Championship club.
"A lot of those things will be decided in January," said Eagles boss Burley.
"It will be down not just to myself but the player and their own club as well. Alex has certainly done very well for us so far though.
"He is very much a 100 per cent man no matter what position he plays.
"He is strong and quick and he has done really well for us.
"Midfield is his favourite position but he has shown how good he is at full back and centre half as well."