A majority of top-flight clubs voted against proposals to increase the numbers of substitutions back in August, despite allowing five in-game replacements during last season's Project Restart.
Manchester United and other clubs competing in Europe this season are permitted to use five substitutions in the Champions League and Europa League, with Solskjaer using his full quota in Wednesday's 5-0 win over RB Leipzig.
The United manager believes that the Premier League should have adopted the same rule in the interests of player welfare, with games coming thick and fast due to the pressures of the pandemic on the football calendar.
"I don't understand and cannot believe that the vote went against," Solskjaer said on Friday, ahead of Arsenal's visit to Old Trafford. "We have to look after the players. This season is the most demanding season of all.
"I can see the point why clubs voted against but take a step back and think about professional footballers, think about their mental and physical heatlth.
"I know Pep [Guardiola] has been talking about it and other managers. We as managers, clubs, staff, we have to look after them. That's why we have to rest players at certain times. So yeah, I would've liked to have five subs."
Solskjaer's Manchester City counterpart Guardiola said earlier this week that the number of muscular injuries had seen a sharp increase due to the demands on players and lack of recovery time.
“On Sunday everyone got the statistics that in the Premier League we have 47 per cent more muscular injuries than the same period last season,” Guardiola said ahead of City's Champions League trip to Marseille.
“If people can reflect this it protects the players, if we don’t it will increase. If we don’t it will be the same in January. We have to protect them as best as possible. The strongest will ones survive, the others will fall down.”