Heart to debut teenager

Melbourne Heart coach John Aloisi said teenage defender Jeremy Walker could make his debut in Sunday's clash with Sydney FC at Allianz Stadium.

Melbourne Heart coach John Aloisi said teenage defender Jeremy Walker could make his debut in Sunday's clash with Sydney FC at Allianz Stadium.

Heart have lost regular starters Michael Marrone, Richard Garcia and Aziz Behich to international commitments, with the trio selected for Australia's East Asian Cup qualifiers in Hong Kong.

Tasmania-born Walker, 19, who joined Heart's youth team at the start of last season, has been named in an extended squad for the trip to Sydney.

"There's an opportunity for him because we haven't really got a right back," Aloisi told reporters.

"We've been trying David Vrankovic at right back, but it's not his natural position.

"We don't really want to put players in a position that they're not comfortable with or haven't played a lot of football there in recent years.

"Thommo (Matt Thompson) did play there for Newcastle, but that was quite a long time ago.

"I'm not really big on making a lot of changes to our structure because I think our shape has been really good."

Aloisi said Sam Mitchinson was set to replace Behich at left back, while Golgol Mebrahtu or Ben Garuccio could feature on the wing.

Heart conceded the lead twice in a 3-3 draw with the Newcastle Jets at AAMI Park on Saturday, prompting a tough week on the training track.

"The other day when we had our conditioning day was probably the best session of the year, so they've responded really well and I'm happy with where we're at," Aloisi added.

Sydney are rooted to the bottom of the ladder with just six points from eight matches, but Aloisi expects the Sky Blues to come out firing under new coach Frank Farina.

"They haven't had a good run of late," he said.

"(But) they're not as bad as what people are saying they are. It's because everyone expects Sydney to be up the top.

"It's always a dangerous time to play a side when they've just appointed a new coach. He hasn't got time to work with them, but he can give them one of those talks to pump them up."

Heart winger David Williams said he was wary of facing the unknown against Sydney, who have never beaten Heart in six attempts.

"They're not going through the greatest run but nor are we," he said.

"With the appointment of the new coach, the players will be thinking different things here and there.

"I think they'll be all over the place, but we can't expect that because if we do we're going to be caught out."