Karl Robinson has made Charlton’s League One clash against Pompey next weekend his priority.
The Addicks travel to AFC Wimbledon in the FA Cup second round on Sunday, before facing Swansea under-21s in the Checkatrade Trophy second round two days later.
A victory at Kingsmeadow would mean the possibility of Charlton facing a Premier League side in the third round of the historic competition.
But with promotion from League One Robinson’s main objective this season, he admits the encounter against the Blues on December 9 at The Valley is his side’s ‘next big game.’
The Addicks boss told Kent Live: ‘We are not going to win the FA Cup. We will do our damndest to try and beat Wimbledon obviously.
‘I certainly want to win, as you know.
‘But we will then make 11 changes at Swansea on Tuesday from the team that play on the Sunday.
‘The big one for me is Portsmouth here on December 9.
‘That’s our next big game.’
Pompey have sold out their allocation of tickets for the League One game at Charlton.
Kenny Jackett’s side defeated the Addicks 1-0 in the Checkatrade Trophy earlier this month.