"There's been a lot made of the discipline, but there's been no big crackdown," said Shearer. "All we ask is people to be in on time at 10am.
"There was a fine system in place, and I've increased that because I didn't believe the previous one was working. I don't believe that's too much to ask people."
Shearer would not elaborate on the reasons behind Barton's suspension, but he is confident the fall-out has not distracted his squad for their biggest game of the season.
He said: "Joey Barton's been suspended until further notice. The club wants to look at a few things and won't make another statement until the time is right.
"There are more important things than that going on this week. It hasn't affected us, to be honest.
"The mood around the place has been good despite the result, Training's been fine."