Solskjaer admits some of the members have been below their best, leading to an overall drop in their form in recent matches.
The team unconvincingly won their last English Premier match 2-1 at home against West Ham United and were tossed out of the Champions League this week after a 3-0 second leg loss to Barcelona at Camp Nou.
Among those that have been singled out by Solskjaer is Frenchman Antony Martial, whom the boss feels has not been 'good enough'
"I’ve spoken to individuals and they know and Anthony is one I’ve spoken to, what we expect from them," said Solskjaer.
"Anthony’s got a massive talent, got a new contract he knows we believe in him, so just keep working," he added.
Martial last scored for United in their 2-1 win over Watford and won the second penalty in their 2-1 win over West Ham last week on Saturday.
United travel to Goodison Park on Sunday to take on Everton in a must-win clash, and Ole Gunnar will hope to have his men all in good shape.