Haussler underwent arthroscopic surgery in Austria on December 31 to remove the synovial plica and patellar cartilage but needs further treatment after time at a training camp in January "caused a significant slowdown of the recovery program" according to Bahrain-Merida. He is back riding his bike but he and the team have opted for a careful and gradual recovery.
The experienced Australian classics rider joined the new WorldTour team from IAM Cycling, but is yet to race in his new red and blue Bahrain-Merida colours.
"All I can really say is that I still have problems with my knee and I'm doing many different therapies, exercises and physio to try to resolve the problem so I can start racing again," Haussler said in a statement from the team. "It has been going on for many months now but I am doing everything possible to get back to a level where I can start racing again. I'm back on bike at the moment and small steps have been made but I will still need some more time to heal 100 per cent."
Team doctor Carlo Guardascione gave more detail about Haussler's problem. "The accidental injury, which occurred at the end of November 2016, caused him severe left knee sprain with capsular edema. The first examinations, including MRI showed an important edema by impact of the left femoral condyle and a suspicion of cartilage damage.
"The same knee has been injured in the past. All specialists that he has seen, including an arthroscopic surgeon, proposed therapies can't give an exact date for his return. We will need to be patient and see how it will goes in the following weeks and how the knee reacts with the proposed therapies and adequate training program."
Haussler was expected to lead Bahrain-Merida's cobbled Classics squad. That role has fallen to Sonny Colbrelli and Niccolo Bonifazio.
"We are all very sorry that Heinrich cannot join us on the races for now," directeur sportif Tristan Hoffmann said. "We miss his spirit, his experience and leadership skills. For now, all we know is that he needs time to heal properly and we are not sure yet when he will be able to race again."