The knee and ankle injuries Ifill suffered in a practice game on Tuesday night are not as serious as first feared.
He had a scan today and Phoenix physiotherapist Wayne Roberts said the prognosis was better than expected.
"Paul has a small tear is his right medial collateral ligament," Roberts said.
"There is also some bruising in his right ankle.
"He is likely to be out for three to four weeks and there is a 50-50 chance he could be available for the start of the season.
"It is better than I expected and we will just have to see how he progresses from here."
Phoenix head coach Ricki Herbert was relieved the injury wasn't serious.
"It didn't look or sound too good so I'm really pleased it isn't as bad as it could have been," Herbert said.
