The trio have slowly recovered from respective hamstring, calf and hip flexor injuries.
Ebert has spent the longest period away from the game after undergoing adductor surgery during the pre-season.
A calf injury set his return back several weeks.
Pittard was a late withdrawal from the Power's Round 5 game against the West Coast Eagles - initially with hamstring soreness - but an injured hip flexor has left him resigned him to the sidelines since.
Cassisi has been absent from the Power lineup since injuring a hamstring against Carlton in mid-May.
The return of Cassisi and Pittard is good news for the Power which has lacked senior defenders for several weeks, despite the emergence of talented young backs in Tom Jonas and Jack Hombsch.
Jarrad Redden has been eased back to training since injuring his shoulder against the Western Bulldogs and remains a chance to play again this year.
But high performance manager Darren Burgess says the ruckman will be evaluated again on Wednesday before any decision on the rest of his season is made.
"We'll assess him again at training on Wednesday," Burgess told portadelaidefc.com.au.
"We trained him late last week and will see how he goes at our main session this week before was make any further decisions on him."
UPDATE 6:35pm Monday 17 June
Travis Boak dislocated a finger against the GWS Giants on Sunday and is set to miss the next two matches against Sydney and Collingwood.
Read the update on Boak's surgery.
Cameron Hitchcock rolled an ankle in the first half before being substituted from the match and will also be evaluated.
Port Adelaide injury list as of Monday 17 June 2013
Jasper Pittard - hip flexor (available)
Dom Cassisi - hamstring (available)
Brett Ebert - calf (available)
Jackson Trengove - foot (2-3 weeks)
Jarrad Redden - shoulder (assess)
Travis Boak - finger (assess)
Cameron Hitchcock - ankle (assess)
