United initially expected Lukaku to return in time for the end of the Premier League season but the 25-year-old opted to stay an extra week in Belgium to continue his rehab.
This season has seen Newcastle re-establish themselves in the top tier, and a win at home to Chelsea from Sunday's final fixture of the campaign should see them secure a top-half finish. "You'll have to ask the club about that", Conte added.
Chelsea coach Antonio Conte has said the departure of the team's former Technical Director Mike Emenalo made the season hard for the Blues.
"When you are at the end of the season, this performance can happen, but the first person to answer for this must be the coach".
Conte conceded the fifth-place finish Chelsea are on course for is not good.
He has effectively guided a Championship-level side to 10th place in the Premier League and only served to enhance his already stellar reputation.
Question marks also remain over the future of Newcastle boss Rafa Benitez, who is set for key talks with the club's owner Mike Ashley in the next week to discuss his potential summer transfer budget as he looks to build on an encouraging campaign.
Chelsea and Man United fight for the last piece of silverware, with both needing it to put a shine on their season.
"As a player, I would be disappointed [if he leaves]. Since the start of the first game, I think. the time I start listening to the speculation about me, this is the moment I start to be anxious".
"I'd certainly like to think people gave their all today, and to not do so would be extremely disappointing", Cahill was quoted as saying by BBC Sport.
"My task is to work, to do my job in the best possible way with these players for the fans".
The Blues needed a win to have any hope of finishing Top Four.
"Since he's been here, everything has been positive: promotion and then the first season in the Premier League we've survived comfortably".