Pompey are uncertain of what to expect when they meet the League of Ireland outfit on Wednesday night.
UCD last played on Friday night when they picked up a 1-0 win over Finn Harps and travel to Derry on Friday evening.
Jackett intends to play two different sides in each half in their first pre-season outing, and, whatever their opponents decide to do, feels they will offer a useful challenge.
He said: ‘You trust them to put out a competitive side.
‘It could be a mixture but we’re playing two 45-minute teams anyway.
‘So if they do something similar we don’t particularly mind at that time and we’re appreciative of the game.
‘We do need a game in the middle of that week, so whatever team they put out may be revolving around their fixtures.
‘Sometimes they play their first team because it’s better than training or sometimes do the pre-season one of getting to 60 or 70 minutes and start subbing them.
‘I don’t know what their plan is but we accept whatever they do and appreciate the game.’