Alfei, who had a spell at the Blue Square Premier club last season, will remain there until January 7.
"I'm looking forward to it," he said. "I need to get a few more games under my belt and hopefully I can do that at Wrexham.
"I enjoyed my time there last season, although I didn't play as much as I would have liked because of a hamstring and back injury. I got to know the lads well and it will be nice to see them again."