South Africa-born McKerr joined Derbyshire on an initial 28-day loan deal on 31 May.
The 19-year-old took 14 wickets in two first-class games for Derbyshire.
He also became the youngest player in the county's history to take 10 wickets in a match when he took 10-141 in their defeat by Northamptonshire.
Meanwhile, Derbyshire opening batsman Luis Reece is still hopeful of being fit from a viral infection for the county's next game, the inaugural day-night Championship game against Glamorgan, in Cardiff, starting on 26 June.
Reece, 26, did not bat in either innings in Derbyshire's three-day defeat by Northamptonshire at Wantage Road on Sunday, after leaving the pitch on Friday with breathing problems.
"I was struggling to breathe," the winter signing from Lancashire  told BBC Radio Derby. "Then, a couple of overs later, I felt tightening in my chest, the paramedics were on and I was off to Kettering Hospital.
"They think it's a viral infection and it was fluid that caused the tightening of the chest. I can't do any strenuous exercise and I'm being referred to a cardiologist.
"But hopefully I will be available for the next game. I'm hoping that it's not going to be a long lay-off. And I'll know more once I've seen the cardiologist."
Surrey have recalled paceman Conor McKerr from his loan spell with County Championship Division Two side Derbyshire, with immediate effect.