On January 23rd, Ross Pearson tweeted confirmation that he had suffered a knee injury in training, which would require surgical repair, and that he was out of his upcoming rematch with Melvin Guillard. He later revealed the extent of the knee injury.
Surprisingly, he revealed that he expects his recovery to last only 4-6 weeks. At first glance, this seems like a very short recovery time frame, especially if he is having one or both of the torn ligaments repaired along with the meniscus. Compare that time frame to the return of Anthony "Lionheart" Smith. In his first (and only) UFC fight in June 2013, Smith suffered a torn LCL due to a knee bar at the hands of Antonio Neto. He returned to training 3 months later, and did not return to fight until December 2013. If Pearson's surgery will be to repair the meniscus injury only, the 4-6 week time frame is more understandable. Injuries to the MCL and LCL are usually allowed to heal on their own without surgery, depending on the severity of the tear.
Ross recently posted an Instagram video of himself engaged in an upper body workout. He is wearing what appears to be a simple knee brace, definitely not a brace that would provide significant medial-lateral stability, as would be expected if he had complete ruptures of the MCL and LCL and was awaiting surgical repair of both.
Pearson's last bout was a no contest affair against Melvin Guillard at UFC Fight Night 30.