Bristol City are expected to be without right-back George Tanner for at least a month after the 22-year-old suffered a recurrence of the hamstring injury which kept him out of action in November.
Tanner left the field in the 39th minute against QPR on December 30 and although he was able to leave the field walking on his own, Pearson feared the injury was similar to the one sustained during the last international break of the year.
That problem, which was ruled as "minor" at the time, kept Tanner on the sidelines for four weeks, missing four matches, and, speaking after City's 3-2 win over Millwall, Pearson - albeit briefly - stated this latest issue will likely be a longer absence.
City have been plagued by hamstring problems for the last 18 months, predating Pearson and head of medical Dave Rennie's time at the club.
After the issues under Andy Rolls last term, the numbers have been reduced but Tanner, Andy King, Joe Williams and Han-Noah Massengo also suffered hamstring injuries this season.
Tanner's previous absence in-part led to a change in system for Pearson with the City manager moving to a wing-back formation and starting playmaker Alex Scott on the right-hand side, with mostly positive results.
Having fielded a back four against QPR and in the first half against Millwall, the Robins' success in the 3-4-1-2 after the break against the Lions, coupled with Tanner being out throughout January, indicates Pearson will switch back to that shape.
Versatile defender Zak Vyner is more than capable of playing as an orthodox right-back, should a back four be deployed, and Pearson does have Danny Simpson but the veteran hasn't featured in City's last four matchday squads.
Williams, meanwhile, making progress from his own hamstring problem with the midfielder having returned to training at the Robins High Performance Centre having not played since October.
But City will be ultra cautious with the 25-year-old given his injury problems since signing from Wigan Athletic in summer 2020.
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