"We did perform some tests at the Mapei Sport Center after the Giro and found that he had signs of a viral infection from earlier in the year," said Max Test, BMC chief doctor.
Hushovd is hoping that the stint of racing in Poland will help him towards the Olympic Games which take place in London after the Tour de France.
"I needed more time to recover and it's always been a goal of mine to do well at the Olympics," Hushovd said.
"I also hope to be a part of the BMC Racing Team's team time trial squad at the world championships and to compete in the road race as well. So there are still a lot of goals left to prove to myself this year."