The 33-year-old was taken off injured during Friday's 2-1 win over Dundee United. He had to be substituted after 34-minutes, Keith Lasley and Josh Law were also forced off through injury.
Pearson remains in Glasgow hospital. He told Motherwell's website, "I'm gutted to miss our upcoming games, but there's very little I can do for this other than rest up."
"I'll hopefully be back as soon as possible to help the lads."