Pompey have handed a debut to Harvey Rew after Kenny Jackett made 11 changes to his side.
The first-year scholar, who last week signed a two-year professional deal, will tonight make a first-team bow against Oxford United in the Leasing.com Trophy.
He joins fellow teenagers Joe Hancott, Josh Flint, Leon Maloney and Bradley Lethbridge in the starting XI.
Holders Pompey having already qualified for the knock-out stages of the competition, yet victory would earn a home fixture in the following round.
Elsewhere in the team, Paul Downing is recalled and given the captaincy.
While Alex Bass begins the first of two matches this week as he covers for Craig MacGillivray, who is away on Scotland duty.
Jackett has named a strong bench for tonight’s fixture, with all six outfield players having featured in Saturday’s 2-1 win at Doncaster.
Pompey: Bass, Walkes, Hancott, Downing, Haunstrup, Cannon, Rew, Williams, Flint, Maloney, Lethbridge.
Subs: McGee, Evans, Harness, Raggett, Close, Harrison, Burgess.