Cedrick lost his place in the team under former coaches Pepe Mel and Juan Carlos Garrido but has returned to the team under Argentinian boss Calderon.
"From day one he transmitted a good mood to the team and there's been a great connection between him and the players," Cedrick told Marca.
"We were in a very difficult period and he told us to train with joy and enthusiasm and got the team going again."
Asked whether Betis, bottom of the Primera Division and eight points from safety, could still escape the drop, Cedrick said: "Yes, it's difficult, but we still believe, because if we had no hope at all we wouldn't bother playing any more."
Despite their domestic struggles, Betis look set for a place in the last eight of the Europa League after winning 2-0 away to local rivals Sevilla on Thursday night.
Elche full-back Edu Albacar has been ruled out of action for between four and six weeks after partially damaging the ligaments in his left ankle.
It was originally thought that the 34-year-old had sprained his ankle after getting injured in last Saturday's training session, forcing him to miss the 1-0 defeat at Espanyol the next day.
He was told he would be out for no more than two weeks, but the latest diagnosis revealed the injury was more severe, handing a big setback to Elche, who are now just three points away from the relegation zone after losing at Espanyol last weekend.