Ahead of Sunday night's huge clash between Castro's Perth Glory and Ninkovic's Sydney FC at nib Stadium, we crunch the numbers with Opta Data to compare these two superstars of the league.
Castro has scored 10 goals and Ninkovic eight, though Castro's tally includes three penalties.
He scores a goal every 172 minutes he's on the pitch, while Ninkovic's number is 250 minutes.
Castro has taken more shots (38 to Ninkovic's 32) but the Serb's accuracy is noticeably better at 59.4% compared to 42.1% for the Spaniard.
Ninkovic has a clear lead here, assisting 10 of Sydney FC's goals compared to just four for Castro.
The Sky Blues midfielder is third in the competition for combined goals and assists, with his 18 behind just the Victory pair of Marco Rojas (23) and Besart Berisha (22).
Overall though, Castro has created more chances for his team-mates, with 55 to Ninkovic's 40.
Ninkovic has played nearly 200 more passes than Castro (978 to 788), but Castro is more accurate.
He passes with 78.9% accuracy compared to Ninkovic's 76.1%, with 76.6% of his passes in the opposition half finding their mark (Ninkovic 73.3%).
THREAT TO OPPOSITION
The tricky Spaniard has embarked on 49 successful dribbles this season, compared to the Serbian's 27.
Not surprisingly, each is the most fouled player in his side as opposition teams often cross the line in order to quell their respective threats.
Castro has been fouled 58 times this season and Ninkovic 51.
While employed largely as attacking players, both lend a hand in defence when called upon.
Ninkovic has made 42 tackles to Castro's 35, but the Serbian's tackle success rate is much higher - 73.8% compared to 51.4%.
The Sydney man has also made far more interceptions, with 36 to Castro's 10, which is probably due to the slightly deeper role Ninkovic plays for his side.
Castro prefers to let his feet do the talking, having won just a solitary aerial duel all season. The slightly taller Ninkovic has beaten an opponent in the air 20 times.
Both players have conceded exactly the same number of fouls (29) and both have received just four yellow cards.