"I know about it since yesterday. I'm here to be in the toughest competitions, that's why I'm at Chelsea," Tuchel told a news conference ahead of Tuesday's Premier League encounter with Brighton & Hove Albion.
"I was clearly not involved and my players were not involved in the decision-making process. My role is to be coach, to be focused and we have an important game coming up tomorrow."
Chelsea beat champions Liverpool 1-0 on Thursday to climb to fourth in the table, a prospect that looked bleak when Lampard was dismissed with the team in ninth place.
"It's proven that Chelsea is an organisation and a club that has everything that you need to be successful as a coach and as a football team, so now it's my job to bring out the very best of myself, together with the team.
Chelsea are fifth in the table with 44 points from 26 games - a point below fourth-placed West Ham - and have not lost in seven league matches since Tuchel replaced club great Frank Lampard in January.
"It's of big importance, I hope we can show up with the same mentality and attitude like the tough challenges we've had.
Tuchel has focused on shoring up Chelsea's defence in his efforts to make them more consistent and the London side have conceded only two goals in their last eight games.
"I think it's not a pleasure to play against us but the picture isn't finished. We have a long way to go," he told a news conference ahead of Sunday's Premier League clash at home to Manchester United.
"I think N'Golo fits into any manager's plans on the planet," Tuchel told reporters. "I was desperate to have him in my teams (in the past).
"To see the guy live, to see how he works, how humble he is, the quality he gives to the team. I am so humbled to be his coach. He will start tomorrow.
Werner, who arrived at Stamford Bridge from RB Leipzig in June, made a bright start under former boss Frank Lampard, scoring eight goals in his first 13 appearances in all competitions.
At the moment I can see that his face is a bit closed, I can see that the weight is on his shoulders.