Rowett’s first-choice custodian Matija Sarkic has picked up an injury during his international duty with Montenegro and the seriousness of his knock is being assessed.
The Lions still have Bart Bialkowski and Trueman as their shot-stopping options even if Sarkic remains unavailable.
Trueman, 27, joined the Lions last season and he is yet to make any appearances for the Championship outfit.
Rowett insists that Trueman is only going to get better and also opened up about his ambition and hunger to become the club’s number two goalkeeper.
“I have two very good goalkeepers at very different stages of their careers”, Rowett said to the South London Press about his current goalkeeping options at the club.
“Young Connal is a really good keeper who I think will get better and better.
“He will really start to keep the other keepers at the club on their toes because he is hungry to first be a number two and then a number one in his own right.”
It remains to be seen if Trueman will get his first start on Sunday when Millwall host Leeds United at the Den.