English Premier League side Southampton sent a scout to watch Ghana striker Richmond Boakye-Yiadom in last Sunday's Eternal Derby in Serbia.
Boakye lasted the entire duration and scored a terrific header for Red Star Belgrade to earn a come-from-behind 1-1 draw with rivals Partizan.
It was his third goal of the season in two league matches.
The 25-year-old impressed against the Saints in the summer when he scored for former club Jiangsu Suning in a pre-season match in China.
Jiangsu signed Boakye from the Serbia club for £ 5m last season but agreed to let him go back to Belgrade on a two-year deal when Red Star qualified for the Champions League.
There are reports scouts representing Galatasaray, Borussia Dortmund, Genoa, SPAL, Pescara, Fiorentina Villarreal, Real Valladolid, Getafe, Las Palmas and Lille were also present.