Lundstram has trained with his new team-mates this week following his arrival and is expected to be included in the squad for Saturday’s League One trip to Edgeley Park.
There was also positive news on Okoli, who has been struggling with an injury in recent weeks.
“Caleb is back,” Martin said. “Whether he’s ready for the squad or not, we need to decide.”
Conor Chaplin, however, remains unavailable as Leicester look to bounce back from last weekend’s defeat to Oxford United.
“Conor is still out,” Martin added. “We’re hopeful for next week, but if not then obviously as soon as possible after that.
