East Bengal were consigned to a fourth defeat in five matches after going down 1-0 to the Indian Arrows in Kolkata on Saturday.
Stand in manager Mario Rivera was disappointed with the concentration levels of his players after the loss which sees them languish at the sixth position with 11 points from nine matches.
"I think the result is not good obviously. The team played well in certain time. The players need to keep concentration. After missing key chances we go missing. Then again they play well and again after missing chances they go missing," he said.