The Spaniard has not featured for the Reds since last month, when he was substituted during the 2-1 win over Watford on 30 March, and has been the subject of feverish transfer speculation, as his current deal is set to expire at the end of the season.
But Solskjaer is pleased with the 29-year-old's efforts to recover from his physical issues, and hopeful that he can be available for either the derby on Wednesday 24 April, or for the meeting with Chelsea at Old Trafford on Sunday 28 April.
Herrera's injury problems started during the Liverpool match, when he was one of three players substituted in the first half.