However, the summer signing had recovered sufficiently to take his place on the substitutes' bench against Juventus in midweek, an indication that he is closing in on full fitness.
Barring any setbacks this week, the 28-year-old is expected to again feature among the replacements for the Premier League fixture against former club Manchester United on Sunday afternoon.
Ahead of the highly-anticipated encounter at Stamford Bridge, Sports Mole takes a look at how Lukaku has previously fared when coming up against the Red Devils.
Lukaku's only appearances versus United have been while representing English clubs, meaning that he has not squared off against the North-West giants since his departure in 2019.
Nine of his 12 outings have come while representing Everton, and it will come as a surprise to many that he never netted against United while playing for the Toffees.
In fact, all three of Lukaku's strikes versus United came in the same match, a fixture which took place all the way back at the end of the 2012-13 campaign when he was on loan at West Bromwich Albion.
While the game is known for being Sir Alex Ferguson's last-ever match in charge of Manchester United, Lukaku stole the show with a second-half hat-trick at The Hawthorns, earning the Baggies a famous 5-5 draw.
Remarkably, Lukaku was only on the pitch for the second half, and his sole contribution during nine occasions when he has completed the 90 minutes was an assist for Everton during a 1-0 win at Old Trafford at the back end of 2013.
Lukaku has ended up on the losing side in half of his 12 appearances, helping his respective teams to three wins and three draws in the other games.