Sarri brought the Argentine to Stamford Bridge from from Juventus in January to help bolster his attacking options for the run-in to the season.
The 31-year-old has scored four goals in 12 starts and two substitute appearances since joining.
Chelsea have agreed a price of £31m to take Higuain on a permanent deal or they can pay £15.5m to secure his services for another year.
Asked if Higuain would stay at the club next season, Sarri replied: “In theory, yes.
“It’s difficult to adapt to the Premier League. I think in the next season he will be able to score a lot.”
Earlier in April, Higuain said it was his “intention” to remain with Chelsea next term.
On Sunday, Sarri added: “For a striker it is difficult to get used to the Premier League. I remember Suarez at Liverpool in [his] first season only scored three goals, then 16, then 24.”
Asked whether a deal will happen, Sarri said: “I don’t know. I’m not in charge of the market, so I cannot answer these questions.”
“It’s difficult to adapt to the Premier League”
Sunday’s 1-1 draw at Manchester United left the Blues fourth in the Premier League, three points ahead of United and two in front of Arsenal in the race to secure Champions League qualification.
Chelsea will play the first leg of their Europa League semi-final against Eintracht Frankfurt on Thursday.
“We are fighting for the top four and in semi-final of the Europa League. We have done a good season,” said Sarri. “Now we need to take two very important targets.”
Keeping Higuain may be more of a necessity anyway with the impending transfer ban on the horizon.
Chelsea have been given a two-window transfer ban and fined £460,000 by FIFA for breaching the rules around the transfer of minors.
They are unable to register new players, but are still allowed to sell them.
Chelsea have appealed against the ban, and are currently awaiting the verdict.