The Singapore striker came off worse in a challenge with left-back Cheung Kin Fung during their friendly loss and ended up with a broken leg
The veteran Home United player had to be stretchered off with a broken leg a few minutes before half-time after going in for a tussle with Cheung during the match at Mong Kok Stadium, which the Lions lost 1-0.
Singapore coach Bernd Stange accepted that the injury was the result of an accident after the game at the press conference, as well as Cheung's offer of an apology.
The left-back went one step further in an Instagram posting with a caption to apologise again.
"I have suffered a serious injury before so I know how it feels!" the post read. "So I would like to apologise and wish you (Indra) a speedy recovery!"
The 34-year-old Indra also received the well-wishes of his team-mates.
Defender Baihakki Khaizan posted up a picture of himself and striker Khairul Amri flanking a wheelchair-bound Indra on Facebook that read "Get well soon Indra Shahdan... #shin #facture #football #nightmare #career". Goalkeeper Hassan Sunny, who had a blinder of a game, also tweeted a "get well soon" message, with fans also posting their support on both social media platforms.
Stange described the injury as "very serious" and it is expected that Indra will be out of action for the next few months.