Wardle suffered ligament damage and was limited to a 20-minute cameo as the Dragons were beaten 45-27 at the Stadio di Monigo. The 22-year-old came on as a 52nd-minute replacement for Dan Evans but was back on the sidelines with eight minutes remaining.
The former Cardiff University student still managed to cross the whitewash in that time, however, when he picked the perfect line after Jack Dixon's strong surge four minutes past the hour mark in Italy.
That was Wardle's seventh score of the season and his fifth in the PRO12, with his recent form suggesting there would be more to come despite the fact that he has slipped down the pecking order after a superb start to the year. Wardle has now scored four times in his last five games but he is unlikely to touch down again this term, with the knee problem expected to rule him out until the early stages of next season.
"We weren't very optimistic before Ross had the scan," said Dragons boss Lyn Jones. "The worst case scenario is that he will be out until September.
"It's a blow because Ross has had a decent season. He has worked hard, learnt an awful lot and really developed as a professional rugby player. It's sad that he won't be involved for the rest of the season."
Wardle has played 23 times for the Dragons in his first season of regional rugby but the second half of the campaign has been more disjointed than the first.
Having made his first nine appearances in the midfield and in the starting line up, he has since flitted between wing, centre and a spot outside the first XV, with just four starts at centre since November, with a further two out wide and eight more outings from among the replacements.
His absence from Sunday's Judgement Day clash with the Ospreys - and probably the trip to Llanelli to face the Scarlets and the home tie with Treviso - leaves Jones relative short of options in midfield given that Ashley Smith is also out of action with a foot problem.
Tyler Morgan could be the man to benefit, with the Wales U20 star in line for a first PRO12 appearance as potential back up to starting pair Dixon and Pat Leach.