The former Crystal Palace player does not need an operation on a fractured shin after a collision with Liverpool's Raheem Sterling, but will not return to training until next year
The 27-year-old spent two nights at Royal Liverpool Hospital following his clash with Raheem Sterling in the Latics' 3-0 defeat to Liverpool, but scans revealed the damage was not as severe as first thought.
The player will be wearing a cast on his leg for the first weeks of his rehabilitation, but his Spanish manager believes he is a strong enough person to come back fit and firing for the Premier League side.
"[The injury] not as bad as it could have been, that's for certain," Martinez told to the club's official website.
"It's still a very serious injury and we need to ensure that Ben is given all the time that he needs to make a full recovery.
"The good news is that he won't be out for as long as we initially thought."
After a strong performance in their victory over Tottenham, Watson seemed to have finally earned his place in Martinez's staring XI - but the manager feels the midfielder has the strength needed to overcome the leg break: "With the character that Ben has, he will be able to deal with such an injury.
"Ben has just started to put his stamp on the team and he will be missed in the group because of the type of lad he is," he added.
When Watson was carried off the pitch in agony many onlookers feared his season was over, but the Latics' fans will be buoyed by the news as they look to climb from 16th place in the Premier League.