Antonio Conte will hold crunch talks with Chelsea transfer chiefs when he returns to London.
The Blues completed their pre-season tour of the United States with a 3-1 victory over AC Milan in Minneapolis.
Bertrand Traore opened the scoring at the stunning US Bank Stadium but his effort was cancelled out by Giacomo Bonaventura's free-kick.
But it was Oscar who made his mark on this fixture with a brace.
The Brazilian smashed home a penalty to restore the advantage in the second half before sweeping home Juan Cuadrado's clever pass to seal victory two minutes from time.
Chelsea will now prepare for one final friendly with Werder Bremen on Sunday but new manager Conte is wasting no time in gearing up for the Premier League kick-off.
Chelsea's 3-1 win over AC Milan in pictures:
Oscar is one of the players whose future will be discussed when Chelsea head back across the pond and Conte wants to trim the squad from its current size.
Nemanja Matic, Cuadrado, and French forward Loic Remy are also under consideration with clubs circling.
Conte said: “Oscar is an important player and the season when Chelsea won the title he was fantastic.
“Last season was bad for all the players – not just for Oscar. He is a good player with a great talent but he can improve a lot.
“I see a good attitude and a good will and these 14 days have been important to me because I am judging the players during the training sessions so I can try to find the right solution.
“I think this match told me a lot about this and about the players who we will keep and the players we can send out on loan or sell.”
“This game was important because my ideas are clearer than before.
“Now we go back to London and it's important for me to talk and take decisions about all the players.
“We have 30 players and four goalkeepers. Now we have one game against Werder Bremen and then we must take a decision – and I hope to take the best decision for the club.
“My ideas are very clear now, but first I must talk about these ideas with the club.”
“We go back to London to have a meeting with the club to talk about the club about these two weeks.
“I think I have the ideas very clear compared to two weeks ago. In this pre-season we were 30 players.
“In 10 days we start our league and it is important to have a squad to compete but in the right numbers.”
The showpiece game with Milan opened the magnificent US Bank Stadium – and the billion-dollar indoor arena was full to its 64,000 capacity.
It meant the Blues have been watched by more than 220,000 fans in their three-games tour of the States this summer.