Date of birth
Turnbull joined Pompey in the summer of 2020 on a one-year contract after impressing while training with the Blues.
The American keeper studied accounting at the University of Notre Dame while representing the Fighting Irish between the sticks.
Despite joining the club from across the pond, Turnbull has a strong connection with the Blues thanks to his grandfather, a North Stand season ticket holder for around 20 years.
The 6ft 6in stopper is yet to make his Pompey debut, but featured on the bench for several League One fixtures while Alex Bass was out injured.