Steyn was one of 10 players who took no or little part in the field sessions at the Springbok training camp in Durban, which concluded on Wednesday.
Steyn has been suffering from a chronic knee dysfunction which has been managed by Sharks and upon a request from his franchise, the load on his knee was limited by keeping him out of training.
While the severity of the injury will only be confirmed later in the week, Steyn is expected to miss the June internationals. It is also possible that Steyn could miss the latter stages of Super Rugby, which would be a body blow to the Sharks.
Lock Eben Etzebeth is also likely to miss the June internationals. He needs to undergo approximately three more weeks of rehabilitation before he can be considered for selection to make his comeback after injuring his foot at the end of last season.
“Eben’s situation is a major setback as he’s been one of our best players in the last two seasons,” Springbok coach Heyneke Meyer said via a statement released to the media on Wednesday.
“We’re continually monitoring his injury, because he really wants to play for the Springboks next month. However, he is still young and has a highly promising career ahead and his welfare is the most important to us."
Springbok team doctor, Craig Roberts, said they evaluated Etzebeth's injury at the camp and he did not take part in any of the field sessions.
“We’ve been in discussion with his franchise, his rehab specialist and the foot specialist who operated on him last year. We’re happy with his progress and will work closely with Western Province to ensure he gets back on the field without any risk of further aggravating the injury," said Roberts.
The other players who missed training sessions at the camp were Frans Malherbe (prop), Schalk Burger (loose forward), Willem Alberts (loose forward), S’bura Sithole (centre/wing), Juan de Jongh (centre), Johan Goosen (flyhalf), Bismarck du Plessis (hooker) and Duane Vermeulen (No 8).
Malherbe is struggling with concussion which he picked up in a Super Rugby match a few weeks ago. As he’s not met the criteria of returning safely to playing, he did not participate in any of the training sessions.
Burger suffered a knock to the neck in the Stormers’ last match against the Cheetahs. He still experienced some stiffness in the neck and was withdrawn from training as precautionary measure.
Alberts and Sithole both picked up grade one hamstring strains while playing for the Sharks against the Blues last weekend. These injuries were treated and managed at the training camp.
De Jongh did not train on Monday as he suffered from a bout of flu, Goosen had some stiffness in his neck on Tuesday, while the workload of Du Plessis and Vermeulen were managed during the training camp.
“Player welfare is incredibly important to us,” said Meyer.
“We’ve been working closely with the franchises and have taken the decision not to take any risks with players carrying injuries at this camp.
“Our medical team worked very hard at the camp, performing medical assessments on all the players and ensuring they get the best possible treatment on behalf of the franchises, as four of them are still playing Super Rugby this weekend.
“A final decision on the involvement of all the injured players will be taken later this week, before we announce the final squad for the Incoming Series on Saturday.”
Twelve players who were involved with the Springboks last year, are already out of contention for the June series. They are Springbok captain Jean de Villiers (knee), Scarra Ntubeni (foot), Chiliboy Ralepelle (knee), Frik Kirsten (neck), Pieter-Steph du Toit (knee), Franco van der Merwe (ankle), Arno Botha (knee), Pierre Spies (bicep), Louis Schreuder (hand), Pat Lambie (bicep), Gio Aplon (elbow) and Jaque Fourie (ankle).