Lukaku played the entire game but suffered a thigh issue as Inter drew 0-0 with Shakhtar Donetsk in the UEFA Champions League on Wednesday (AEDT), its first goalless draw in the competition since September 2009.
The 27-year-old had scored in nine straight European matches up until then, while he has already found the net five times in as many Serie A appearances at the start of the new campaign.
However, with a huge UEFA Champions League clash against Real Madrid looming on the horizon, plus a trip to Atalanta to come before the November international break, Conte is wary of pushing the player too hard despite his obvious importance to the team.
"Against Shakhtar he had a muscle problem, precisely when he kicked the free-kick," Conte said on Friday. "He still has this.
"We need to recover in the best possible way. You know very well how important Romelu is for us, especially at a time when Sanchez is also missing.
"We are evaluating the situation and we try to act for the best of Inter.
"We are recovering some players from coronavirus, I have a lot of faith in everyone and I know we can do well and that we must do well anyway."
Sanchez, meanwhile, was withdrawn at half-time in Inter's UEFA Champions League opener with Borussia Monchengladbach on 22 October (AEDT) because of a thigh injury.
The Chile forward will once again be unavailable for this weekend, denying Conte another attacking option for the Serie A fixture.
Inter has not done well against Parma in recent home games either, failing to win any of the previous four matches at San Siro between the teams.
"Sanchez is not ready. You have to wait for the doctors and the player to give the go ahead, because sometimes too much desire to play makes the player make the wrong decision," Conte said.
"You have to be patient and try to experience what happens, especially for the players because, as I said, the players have to take great responsibilities, they have to be aware of the situations.
"Forcing it can lead to negative consequences, both for them and the team."
Inter will be boosted by the expected return of Roberto Gagliardini, who tested positive for COVID-19 earlier this month.
On the midfielder's status, Conte said: "Gagliardini is fine, he trained at home and, when he arrived with us, we did some checks. He is available and I'm happy to have him, because in midfield we had some problems since the international break."