Mauricio Pellegrino has admitted that Southampton were deservedly on the end of a heavy 4-1 defeat against Leicester City, describing it as an "awful day" for his side.
The Saints shipped three first-half goals in a home Premier League match for the first time since April 2005, as former boss Claude Puel made a winning return to St Mary's.
Under-fire manager Pellegrino was unwilling to hold back when commenting on Southampton's display, but is hopeful that his players can now respond when travelling to Chelsea on Saturday afternoon.
"It was a really bad game from the beginning to the end," he told reporters. "After conceding the first goal they were getting better and little by little our confidence went down. We gave the ball away all the time.
"For me it is a bit about concentration, not being 100% focused and at this level you cannot be on the pitch giving this advantage. It was an awful day and that is the reality.
"In the Premier League, there are a group of teams where the gap is four or five points and we have to fight. Obviously, we have the same feelings as the supporters.
"Three days before we played a good game [against Arsenal] but in football in three days everything changes. We need to react now."
Southampton are 11th in the Premier League table after winning one of their last eight matches.
