Tuchel pulls no punches as he reacts to 2-1 loss at Southampton.
Raheem Sterling got his third goal in two games in Chelsea colours to fire Tuchel’s side ahead in the 23rd minute.
But it was a short-lived lead as another former Manchester City man, teenager Romeo Lavia, levelled to become the first player born in 2004 to score in the Premier League.
Adam Armstrong then ended his 22-game drought with a goal on the stroke of half-time, and Chelsea could not find a response after the break to leave them already off the pace in the table.
Tuchel didn’t hold back in his criticism after a second Premier League defeat of the season in just their fifth game and these comments left little to the imagination.
"It is not enough to win away matches, it is not enough to play 20-25 minutes on the level we want,” declared Tuchel. “It is too easy to put us off balance, to beat us, to confuse us. It is too easy. It happened against Leeds. We need to understand why and find solutions.
"We lose concentration, we lose our plan and lose consistency, it is too easy to beat us.
"A lot of key players are injured, it is something I don't really understand. You can always lose football matches and I am humble enough to admit this but in a match where you are in the lead there is no need to give away half chances. To have no answers in the second half was disappointing.
"We need to have answers, we need to step up and play a level higher if needed. We struggled to do this.
Tuchel went on to suggest the defensive side of Chelsea’s game is their big weak spot, as he continues to push for more arrivals in this summer’s transfer window despite spending more on new players than any other side in European football.
"Soft, soft, soft defending,” he added. “There is no need to give shots away. Just toughen up as a team and show a different mentality.
"Obviously we’re not tough enough at the moment to win these matches away. One set-piece again. One sloppy defending again. Then we are off balance. We were not tough enough as a team to react or push it over the line for us.
"The line is so thin before excuses and explanation and I don't want to go down this road because I don't want to give anybody – myself, staff, players – any room for excuses. The closing of the transfer window will help as we know the commitment.”
Tuchel’s comments were unusually pointed and it will be fascinating to see how his players and the club's owners react to his effort to draw a response from his team and possibly put pressure on the Blues board to deliver new signings.
Chelsea might be a team in transition with more big-name and big-money arrivals just around the corner courtesy of bullish new owners Todd Boehly and Behdad Eghbali.
But the top-four-hunting Blues should still not be in the business of losing a clash like this against a remodelled and youthful, but admittedly gritty, Southampton.
Chelsea can expect to slip further down the embryonic table after Wednesday’s fixtures, with Tuchel’s rebuilding job clearly boasting great promise but not yet delivering.