SOCCEROO Eli Babalj could be set for a shock return to Melbourne Heart within days.

The Sunday Herald Sun understands Serbian club Red Star Belgrade is yet to pay the final instalment of the $400,000 transfer fee, which was due last month.

While failure to pay the entire transfer fees seldom leads to a return to a player's original club, Heart inserted a contractual clause stipulating Babalj's return should Red Star fail to pay the full amount.

Heart, which sold Babalj in June, is believed to have received slightly more than $300,000, meaning Red Star owes the A-League club just under $100,000. Red Star is in financial strife.

The striker returned for Red Star's mid-season break a fortnight ago but has remained in Belgrade while the rest of the squad is in Turkey for a mid-season camp. The Serbian season resumes late next month.

He has been in regular contact with Heart officials this week. The Heart board this week sanctioned a long-term deal to be offered to Babalj should he return.

Babalj, 20, has made just six appearances for Red Star, all from the bench. Alarm bells were ringing when Robert Prosinecki, the coach who signed him, was sacked on the eve of the season.

New coach Aleksandar Jankovic signed two new strikers and Babalj has been left on the outer. Babalj's return would be a huge boost for Heart coach John Aloisi in his bid to have Heart finish in the top six.

He scored nine goals in 22 A-League games last season after missing the opening month with injury and then made his Socceroos debut last November against Korea.

Midfielder Vince Grella will train with the squad this week, which could be timely given Heart will lose skipper and playmaker Fred for four weeks with a quadricep injury suffered in Friday night's 2-0 win against Adelaide.

Originally published as Babalj could return to Heart