Southampton boss Ralph Hasenhuettl said on Friday the Premier League decision to increase the number of substitutes on the bench does not help if teams cannot make five changes in games.
Calls from top-flight managers to adopt IFAB's temporary rule change to allow five substitutions per match given this season's hectic fixture schedule failed to meet the threshold of 14 votes in favour at a meeting of the 20 clubs.
The league only agreed in principle to introduce additional permanent concussion substitutions, while the number of players allowed on the bench was increased from seven to nine.
"We take it how it is, we were hoping for five subs. I was always a friend of more subs. Even in Germany I was positive for more subs," Hasenhuettl told reporters ahead of Saturday's home game against Manchester City.
"Especially in this time over Christmas it would be helpful. Having more subs on the bench is not really helpful. When we have this intense three games a week schedule, then it is definitely something that could help you."
The Premier League is the only major European league to revert to a maximum of three substitutes while the others have continued with five.
"We must always be careful. We have a few players who are coming back from longer injuries and three games in a week over 90 minutes is not a good idea," Hasenhuettl added.
"But it depends how fit the player is. We have a few tired bodies, but the rest are ok."
(Reporting by Rohith Nair in Bengaluru; Editing by ken Ferris)
