Adelaide United left-back Cassiohas labeled Friday night's clash with Melbourne Heart as a must-win.

The 30-year old Brazilian, now in his fourth season at the club, understands the enormity of going into a round 3 fixture at home without a win on the board and believes the Reds need to take maximum points against the Heart.

"I think we have to win," Cassio said.

"It wasn't a bad result against the Central Coast, but I think this Friday we have to win because we play at home and I think the crowd will help us.

"We had a great first half and we showed a lot of good things, and now I think we're ready for our first win, but we know Melbourne Heart is a good team so we'll be doing everything to win this game."

Adelaide drew their opening round match 0-0 with the Newcastle Jets before recording another stalemate last week. This time, however, it was 1-1 with the Mariners after defender Iain Fyfe had given them the lead but they gave it up in the dying minutes which Cassio rued but admitted it may have been the right result.

"We're really disappointed because we had the game in our hands, and we lost the three points in the last seven minutes," Cassio added.

"In the end we knew the Central Coast is a good team, they always fight back and at the end of the day I think it was probably a fair result."