Chelsea manager Thomas Tuchel said one reason Christian Pulisic hasn't been in his starting XI is that he is "strong" coming off the bench, following his team's 2-0 win over Everton in the Premier League on Monday.
Pulisic, 22, came on as a very late substitute for Chelsea and has played just 134 of a possible 810 minutes since his former manager at Borussia Dortmund arrived to take over for the departed Frank Lampard.
"Maybe Christian's problem is I know from Dortmund how strong he is from the bench," Tuchel said after the match. "I think he started only in the cup game and in the end that's my responsibility and my fault. It's a bit unfair because I know what an impact he can have in 20 or 30 minutes. He was a bit unlucky in the last games but there's no lack of trust or quality. He just has to be a bit patient.
'We also have another guy I would love to mention, which is Emerson [Palmieri], who suffers from bad decisions against him from me. He does not play but he is an amazing guy who trains at the highest levels and never lets the team down with his mentality.
"This was a super hard decision today to have him out of the squad and the same with Tammy [Abraham]. It tells us we are a strong group and the guys just have to keep on fighting."
Tuchel said in February that he understood Pulisic's quality and wanted to keep him at Stamford Bridge, but that no decisions had been made over the U.S. international's future thus far.
The German boss was also keen to compliment his defence after their win over Everton -- Tuchel extending his unbeaten run as Blues boss to 11 games, including clean sheets in nine of those games and five in a row at home in the league.
"It's about principles, it's about being reliable, it's about trust that your back is covered if you step out and attack up front," Tuchel said.
"It's a high quality of defending right now in the group and of course they're super hungry to fight to not give chances away because it's a good feeling and it makes us self confident."
As well as beating Everton on Monday, Chelsea have also recently stopped Liverpool and Manchester United from scoring in the league and Atletico Madrid failed to get past the Blues' back line in the Champions League.
That defensive consistency belies how Tuchel has chopped and changed who plays in front of goalkeeper Edouard Mendy, alternating Marcos Alonso and Ben Chilwell at left-back and on Monday replacing Antonio Rudiger with Kurt Zouma in the back three.
"It's not about having clean sheets and parking the bus in front of a goal," the German said. "It's about a certain style of defending and we try to defend up as high as possible to have high ball recoveries...It's about trust, it's about courage."
Information from Reuters was used in this story.