The Belgian returned to Stamford Bridge in the summer window, signing from Inter Milan in a deal worth £97.5million.
Lukaku got off to a stunning start back in English football, netting three times in as many Premier League fixtures, as well as scoring the winner in the Blues’ opening Champions League group game.
Since then, he has gone four games in all competitions without a goal and has been visibly frustrated during their two defeats this week.
And speaking ahead of their clash with Southampton, Tuchel has suggested that Mason Mount and Mateo Kovacic are the only team-mates that have been effectively linking up with him.
Asked if Lukaku looking isolated was to do with him still adjusting to new surroundings, Tuchel said: “Yes and no. He was fully involved in the first game against Arsenal, the second half against Tottenham he was involved in creating chances for Timo Werner, Mason in the first half.
“I think that football right now is about connections, Romelu I feel has a strong connection with Mason Mount and Mateo Kovacic.
“They look for each other and have an understanding, everybody else maybe lacks it a bit so they need to learn and understand and adapt, create better of course.”
The German boss continued: “Like I said, we have games where he was fully involved but now we have games like against Manchester City where of course he was isolated, City made him that, our transition did that as well. There will always be matches like this. There is no place to go.
“Sometimes you have these games so maybe this one is not a reference game. We will talk maybe totally different if he had scored in the 80th minute [against Juventus] which was a chance he normally scores.
“It is right but nothing major to worry about. We are aware of it.”
Mason Mount has missed both of Chelsea’s defeats this season, but is back in training and could be involved against the Saints.
“Mason is in the squad, Mason is back, it was not a long injury, was a minor injury, and we’re happy that he’s back,” Tuchel confirmed.
“Then it’s obvious, a given that he’s nominated and he’s happy to be nominated and will give everything to do his best for his England squad.”
On how much his side missed the midfielder, the Chelsea manager added: “We need to be careful. He had a rough time at Tottenham.
“It is not on single players. Of course, we want to have Mason on the pitch and we know the energy he gives and we miss him but we cannot start reproducing performances on the thought of players who are missing.”