Brown has impressed since arriving at Brisbane Road last month following an injury to regular number one Jamie Jones, and was outstanding in last Saturday's 2-1 win at Tranmere.
But Jones played for the reserves in midweek following hernia surgery and his return could spell the end of Brown's stint in east London.
"A lot depends on how quickly we get Jonesy back and fit," said Slade.
Source: PA
Source: PA