Paris - Quick Step cyclists Belgian Laurens De Plus and the Czech Petr Vakoc were recovering in hospital after being knocked down by a truck in South Africa, the team said on Friday.
Neither rider is in danger but Vakov, 25, was left with broken vertebrae and De Plus had lung and liver injuries.
Both are expected to remain in hospital over the weekend.
The pair had been out riding on Thursday with team-mate Bob Jungels, who rushed to their aid and comforted his team-mates until medical care arrived.
"I did not see the truck coming from behind, but it must have hit them with the left front mirror or even the front left part.
"I ran to them and could see they were injured, so I did not dare to move them.
"A lady who was on the side of the road came and helped us, calling the ambulance, while our trainer Koen and I talked with them. It was really tough," Jungels said in a team statement.
Last April top Italian rider Michele Scarponi was killed in a road accident near his home.