The Brazilian, such an important cog in the centre of the park for the red and whites, limped off 10 minutes into the second half. Heart officials initially said he had hurt his calf but scans on Saturday confirmed a left quad strain for the 32-year-old, who has also struggled with a hamstring problem this season.

For a team that had won two of its three games since the turn of the new year, there had been plenty of negativity around Heart leading into its clash with high-riding Adelaide United at AAMI Park.

The critics had seized on the team's late collapse against Sydney a week earlier, when it shipped two goals in the dying minutes to lose to the bottom team, to suggest that John Aloisi's side lacked the mental strength and commitment needed to be a finals contender.

There is a thin line between success and failure, and too often this season Heart has fallen on the wrong side, conceding late goals to give up wins, or letting the opposition score in the dying minutes - as Sydney did and as Melbourne Victory did a few weeks earlier - so that they gain three points and Heart nothing.

Aloisi's players went some way towards shutting up the naysayers in that 2-0 win over Adelaide.

They played with conviction, organisation and commitment and were good enough this time to not just take their chances but to shut down a game they controlled.

They were assisted by a lacklustre showing by the Reds, who played only in patches. But credit must be given to Heart for shrugging off the disappointment of that loss to Sydney and regrouping off a short turnaround to stop a team in minor premiership territory from playing.

Aloisi said that keeping a clean sheet was a good sign, as was the resolution displayed ahead of the battle for finals spots. On this performance, the former Socceroo striker said, Heart could be a match on its day for any side in the competition.

Given that it has seen off defending champion Brisbane twice, even though the Roar does not look the team it was last year, defeated Adelaide and been highly competitive against Melbourne Victory, he might not be far off the mark.

Certainly Adelaide boss John Kosmina agreed. He said after the game that Heart was no pushover and a difficult side to play against.

For Aloisi, the next fortnight - with a game at West Sydney and the third and final derby against Victory - will be a good indicator of whether Heart can build on its decent recent run, the Sydney hiccup excepted.

''It was a good performance considering what happened last week,'' Aloisi said. ''The players were down, a lot of questions were asked about fitness, concentration and whether we're good enough.

''I think the boys showed tonight against the second team, two points off the lead, that we can beat anyone.

''The next 10 games we have to show that we can keep playing like this and be solid, but we'll always be dangerous going forward.''

Kosmina has ruled out an import quick-fix as it faces yet another injury to a key player, with Socceroo midfielder Dario Vidosic limping from the field with a hip injury.

The Reds were already without star import Marcelo Carrusca, winger Fabio Ferreira and striker Bruce Djite through injury, and released former A-League goalscoring machine Sergio van Dijk last week.

Van Dijk was the club's international marquee and creates a vacancy for a high-quality visa player should the Reds want to fish for one in the January transfer window.

But Kosmina said racing to the transfer market to replace Van Dijk was a wrong move as imports usually take time to settle in the A-League and bringing someone into a top-two side with less than half the season remaining could go wrong.

''We'll make do with what we've got for now,'' Kosmina said. ''It's always hard to bring someone, especially if you're looking at a foreigner, in now.''

With aap