Paolo Di Canio has vowed to whip his Sunderland players into shape after the controversial Italian's debut as Black Cats manager ended in a 2-1 defeat at Chelsea on Sunday.
Di Canio's team took the lead on the stroke of half-time through Cesar Azpilicueta's own goal, but Sunderland faded badly in the second half as Chelsea hit back through a Matthew Kilgallon own goal and then Branislav Ivanovic's winner.
Both Chelsea goals contained a large dose of good fortune, but Di Canio refused to dwell on his side's bad luck and instead focused on his players' lack of physical and mental strength.
The former Lazio and West Ham forward has been disappointed with his squad's fitness since arriving at the Stadium of Light last weekend and he said: "We have studied the players and I know exactly what they can give to me in terms of energy.
"It's not the fittest team in the world, but we are going to work and give them more energy.
"We are working to give them something more without causing damage, because we have only a short time from now until the end of the season to build their strength.
"Most important for me was their attention. Both the goals came from mistakes in the head and we have to work on that as well."
Sunderland are now above the relegation zone only on goal difference after Wigan's draw with QPR, leaving Di Canio with six games to save his team from the drop.
But the Italian refused to contemplate the possibility of slipping into the Championship.
"I am not worried (about relegation)," he said. "I knew what players were here but we have to fight until the end of the season.
"I won't say this was a bonus game but it was a test for us to see what we can do. I am not happy we lost 2-1 but there were positive things I can take from this."
Di Canio's appointment as successor to the sacked Martin O'Neill sparked a storm of controversy over his extremist right-wing political views, but he refused to answer further questions on the subject after the Chelsea defeat.
A Sunderland press officer made it clear Di Canio was only willing to answer questions about football at the post-match press conference, yet he still had to deal with several inquiries on the issue and ignored them before beating a hasty retreat.
Chelsea's interim manager Rafael Benitez has sometimes had difficult relationships with his fellow Premier League bosses, but he was full of sympathy for Di Canio's difficult debut.
"The first game is difficult, especially if you play against Chelsea, so we will see how he does in the next few weeks," Benitez said. "I spoke to him and gave him my best wishes."