Castro, who was a notable absentee from Chiefs' squad for their crunch Absa Premiership tie against Sundowns at Orlando Stadium, has been ruled out for the rest of the season.
The Colombian striker had initially suffered an injury against Bidvest Wits in their opening clash of the PSL restart and returned to action in their recent 1-1 draw against Stellenbosch last Sunday.
However, he lasted only 26 minutes before he was forced off with the same muscle injury that had been aggrevated. The club has now confirmed that the 31-year-old will play no further part as Amakhosi look to clinch the league title.
This comes perhaps as a result of the demanding schedule created by the Covid-19-enforced suspension of the season and having to return to action in record time after a four-month hiatus from competitive action.
The former Mamelodi Sundowns star has played a big role in The Glamour Boys' title charge this season, contributing seven goals in 16 appearances prior to his unfortunate injury blow.