Celtic boss Neil Lennon has threatened to ring the changes for Wednesday's Champions League clash with Benfica following Saturday's defeat to St Johnstone.
Despite taking the lead at McDiarmid Park, the Hoops conceded twice to suffer their first loss of the new season.
"I will need to have a rethink for my team on Wednesday night because they are not paid to play like that," said Lennon.
"I've made it clear I want a massive improvement. I will not go back to where I was this time last season and allow disjointed performances. I will not be accepting that."
Celtic and Benfica are joined in Champions League Group G by Barcelona and Spartak Moscow.