"When I looked at the players as they were about to come out for the second half, they looked a bit like a defeated team," he said.
"Their heads were down and I said if they carry on looking like that we would not win the game. It changed them and after that they were a lot more positive."
Two-one down after El-Hadji Diouf and Kevin Nolan had overturned Rolando Bianchi's early effort, City roared back to claim a 4-2 win; their ninth successive Premier League home triumph this term.
Although Bianchi was not on the pitch as Etuhu finished Bolton off, the Italian had major cause for celebration, marking his first start since September with his fourth goal of the campaign.
It has long been predicted Bianchi will leave Eastlands in January, just six months after his £8.8million arrival from Reggina.
"Rolando has behaved extremely well," he said.
"He has not played many games for us but he has always worked hard in training and does what he is supposed to do.
"He always has a smile on his face and today he scored an important goal."
Given the lack of forward options available to their manager, most City fans are bemused by Bianchi's lack of opportunities.
However, Eriksson believes the new boy has found it hard to adapt to life in England, although there are clear signs his settling-in period is at an end.
"It is more difficult for strikers coming into the Premier League," he said.
"They are not used to the pace or the strength of the central defenders. But I think we can see now Rolando is coming on very well."
Bolton boss Gary Megson said: "We have chucked four goals away.
"Andy O'Brien is not Bobby Moore or Franz Beckenbauer but we certainly miss him.
"And if we miss him that much, someone either needs to step up to the plate or we need to bring someone in from outside."