Steenkamp leaves Ospreys
It brings to an end an injury ravaged 14-month spell with the team that has seen the lock restricted to just two competitive appearances at the start of this season.
The 28-year-old signed from the Cape Town based Stormers in September 2014 to add his considerable experience and physical presence to a young squad having earned a reputation as one of the leading line-out operators in Super Rugby.
However, an achilles injury sustained within days of his arrival at Llandarcy Academy of Sport meant that he missed last season in its entirety, returning to full training for this pre-season.
Having come through the summer months Steenkamp then stepped up his involvement with an appearance in the pre-season win over Saracens before making his competitive debut, starting in the PRO12 opener away to Ulster. A second appearance followed off the bench against Munster the following week but he then found himself sidelined once again after reporting hip instability to the region's medical team.
After further investigation, the player underwent surgery at the weekend and, having assessed all options both parties have agreed to the early release.
Steenkamp said: "The way that it has turned out is really frustrating for everybody, really disappointing. Once I'm well enough to travel I will head home to concentrate on trying to get fit again.
"I had high hopes coming to the Ospreys last year. It was a new challenge for me, one that I thought would be a good experience, but injury has meant I haven't been able to have an impact. It's really unfortunate that I can't help the team, particularly at a tough time like this, which is what I was brought in for with my experience.
"Being part of the Ospreys family will always mean something to me, even if I'm disappointed with the outcome, everybody has been fantastic with me since day one and I'll take great memories home with me. It's just a shame I leave without being able to repay the faith they showed in me.”
Ospreys general manager Andrew Millward added: "De Kock leaves the Ospreys with everyone's best wishes. He was signed last year to give a young squad some much needed experience during the periods when we lose our internationals but, unfortunately, was unable to make the desired impact due to injury.
"Losing De Kock was another setback in our plans for this year, to have a spine of experience in the squad, along with losing people like Andrew Bishop and Ashley Beck. Rory Thornton has stepped up to the plate and been exceptional but it is a hell of a workload for a young man with limited topflight experience, the kind of experience that someone like De Kock would have brought to the group.
"When you add in things like the injuries to the Canadians, who we had anticipated coming back in at the start of last month, fresh and raring to go, and the injury to Webby, there's no doubt it's been a challenging time for us, but we'll overcome it.
"We wish De Kock the very best for the future as he recovers from surgery and returns home."