Kerkering (hamstring) threw a bullpen session Saturday, Charlotte Varnes of The Athletic reports.
The right-hander completed his third side session since having his throwing program delayed by a Grade 1 hamstring strain at the start of camp, per MLB.com. Kerkering, who's expected to be one of Philadelphia's primary setup men for closer Jhoan Duran, still has plenty of time to build up in advance of Opening Day.