They should also correct a mystifying Monday selection from the win at Port Vale earlier this week.
Charlton have won their last three third tier matches under former Posh skipper Dean Holden.
Posh started impressively under Darren Ferguson at Vale, but the Londoners are sure to present a tougher test.
The PT has stuck with the same 4-2-3-1 formation used at Vale Park.
9. KWAME POKU
He's become a key man either out wide or by floating across the forward positions as he did with great effect at Port Vale. Photo: Joe Dent
10. EPHRON MASON-CLARK
You can't leave out a two-goal matchwinner. He's only going to get better as his first season as a Football League player continues. Photo: Joe Dent
11. JONSON CLARKE-HARRIS
The skipper needs to improve his hold-up play, but he stays in ahead of Jack Marriott for now. Photo: Joe Dent
12. THE SUBSTITUTES
The absence of Jeando Fuchs (pictured) from the starting XI was just about understandable, but his absence from the matchday squad was baffling. He offers something a bit different to the other midfielders, namely a strong defensive game, which will come in useful against better teams than Port Vale. Will Blackmore is now the only available back-up goalkeeper and he is joined on the bench by Fuchs, Josh Knight, Dan Butler, Marriott, Harrison Burrows and Ricky-Jade Jones. Photo: Joe Dent