The Premier League champions chose to sell Matic to their direct title rivals Manchester United in a £40m deal last week.
Jose Mourinho was in charge for the latter campaign and, despite securing Europa League, EFL Cup and Community Shield glory, along with Champions League qualification, knows they have to do better in the league.
"It amazes me, why would you sell Matic to Manchester United?".
Lukaku had earlier ballooned a shot over the crossbar with the goal gaping but reacted smartly to steer the ball home after Matic's effort had been parried by Keylor Navas.
"Chelsea are weaker than last season - no Diego Costa, no Matic - and I'm concerned for them".
"I think we played everything so we don't lose this game". "But they are very experienced and they also had some chances to score another because at the end we tried to go with everything to score and they had some counter-attacks".
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Spurs are also reportedly chasing Celta Vigo youngster Pape Cheikh Diop, and are still looking for an additional forward.
All of a sudden United are in the driving seat ahead of Chelsea to win the Premier League.
Referring to the club's remaining transfer business, Mourinho said: '25% means one of four, and we got a central defender that can play in many other positions, which is important.
"There is very rarely such big transfers between champions to clubs that are challenging them and it is a unusual move". "But we can take a lot of good things from this game". My idea was to give Bakayoko the right time to adapt in this league behind Matic.
But doubts are creeping in over whether they have enough depth to retain their trophy as well as compete with Europe's elite in the Champions League.
At 29-years-old it could be argued that £40m constitutes good value for Matic but after making 35 appearances last term, it remains to be seen just how much Conte will miss his midfield general.