He faces a battle to keep hold of his place for Monday’s game against Aston Villa when Lampard will make even more changes than originally planned in response to his side’s limp performance at the Emirates.
Chelsea’s manager was so infuriated by a third straight away loss that it eclipsed his anger over the decision to schedule two games in the space of 48 hours over Christmas.
“I’m certainly not going to bang the drum about the turnaround after our performance,” he said. “It’s not the important point.
"But to play two games in two days we have to make changes anyway. Some of them will happen now because of how the game went and people will have to come in and inject the energy and the personality of our normal performances.
“People wanted to talk us up as title contenders – I never accepted that as the case because we are not there. That takes time to build and days like today are certainly ones that we have to learn a big lesson from. Everybody, myself included, because when I see that in the first half, I don’t like it so it can’t happen.”
Werner extended his barren run to 10 games without a goal – and Lampard didn't try to hide his disappointment in a player he has fiercely defended in recent weeks.
“Certainly the goals not going in is always something an attacking player will get judged on,” he said. “For today Timo wasn't giving us enough with or without the ball. Some of it we have to give him time. I keep saying the same thing because it's a different league, but we also have to get there quickly.”
Lampard has already shown his ruthless side by taking Kai Havertz out of the firing line after his underwhelming start at Stamford Bridge.
Now it is Werner who looks like he needs a break.
But he is not alone in a Chelsea team that appears to have lost its way.
A worrying run has seen them win just of their last six in the Premier League – and prompted Lampard to take a leaf out of his former manager Jose Mourinho’s book by publicly criticising his players.
He questioned their character at the Emirates after a defeat which he described as the lowest point of their season – even worse than the 3-3 draw with West Brom in September.
“Today they did (lack character) and the players know that,” he said. “The first half we lacked it.
“The players have to make it different. The message is clear. The basics are to run and to sprint and the players have to do that on the pitch.
“The first half was certainly our worst performance of the season because it lacked the energy and I think at West Brom there were clear errors and a combination of things that went against us in the game and the lads turned it round. Today the way we approached it in the first half wasn’t right.
“I don’t think this season was ever going to be a plain sailing, winning every week. We got confident and we got into a position where we were not losing games and winning a lot of games.
“When you lose a couple of games things become a lot tougher and the only way out of it is the fight and work hard.
“The few defeats we had recently are because we dropped off. The players have dropped off a level. My job is to pick it back up.”