Rashford missed Thursday's Copa del Rey clash against Atlético Madrid as a result of the problem, leaving manager Hansi Flick short of one of his key attacking options.
The 25-year-old has been undergoing recovery work throughout the week, with the club hoping he might return in time for the Girona fixture next Monday.
However, media reports suggest that his availability remains uncertain, and a cautious approach may be taken to avoid aggravating the injury ahead of a busy run of fixtures.
Rashford's absence against Atlético was felt as Barcelona struggled to break down their opponents, ultimately losing the first leg of the Copa del Rey semi-final.
With a derby looming, the club will be monitoring his condition closely before deciding whether to risk him.
Flick faces a selection dilemma in attack, and the uncertainty over Rashford adds to the pressure on the squad.
Diario AS has reported that: "His knee is slightly injured. Rashford is sidelined and his participation in the match against Girona is uncertain."
Hansi Flick has admitted there was a "clear" foul in the build-up to Girona's late winner, but the Barcelona manager refused to hide behind officiating complaints after his side slipped to a damaging 2-1 defeat at Montilivi.
Barcelona head coach Hansi Flick is expecting a strong reaction from his team when they face Girona in their La Liga clash at Estadi Montilivi on Monday.
Frenkie de Jong expressed frustration after Barcelona suffered a 4-0 defeat to Atletico Madrid in the first leg of their Copa del Rey semi-final, a match marred by controversial officiating.
Hansi Flick's tenure at Barcelona continues to gather momentum as the German coach prepares his side for Thursday night's Copa del Rey clash against Atletico Madrid.
