The 21-year-old spent the last six months of the season on loan at Valley Parade and Law - who was playing in the reserves at Bramall Lane - believes McCall rescued him from the wilderness.
"This season has been amazing for me, I never expected to come out on loan and play over 30 games," he told the Telegraph & Argus.
"I'd personally like to thank the manager. He saved my career and I'll remember that forever.
"At the start of the season I was just playing reserve team football and sometimes training with only eight players and at my age that's no good."