I think, as you know very well, you go in the transfer market you have to know that, if you want the best, you have to spend a lot of money.
Bellerin and Maitland-Niles will probably start in the wing-back positions.
However, defender Andreas Christensen has been cleared to play, despite having been substituted at the weekend due to a head injury.
The likes of Gary Cahill (hamstring), Danny Drinkwater and Thibaut Courtois (both ankle) could be in contention as well, although they face a late fitness test to determine their availability.
Pressed on the nature of Morata's problem, he added: "He has a problem in his back".
The match could also serve as the debut for Ross Barkley after the new signing missed out on his chance against the Seagulls.
In midfield, supporters seem to prefer Cesc Fabregas partnering N'Golo Kante instead of Tiemoue Bakayoko, who does appear to be coming into his own.
Sanchez, Mkhitaryan swap completed
Sanchez and Mkhitaryan are not exactly the same sort of player, so perhaps it is unfair to compare their goal returns. Asked about a swap deal , Arsenal boss Wenger said: "It happens only one way, if the other way happens as well".
David Ospina has been undisputed first-choice for the Cup competitions, and Wenger is likely to revert to the Colombian between the sticks for the London derby.
Chelsea have won two Premier League titles and a League Cup in the past four seasons, but Conte stated his belief that teams can still have very good seasons even if they don't land silverware.
Arsenal's impressive Chelsea run to continue?
I could certainly see this game going to pens so my advice would be to split the stakes and back both Arsenal and Chelsea to win on penalties at 33s each, or just back either team at 16/1 if that's an option. The departure of the unhappy Alexis Sanchez and the arrival of Henrikh Mkhitaryan could spark them into life as they look to refocus after losing their star man.
Arsenal may have been the victors on the night, but the biggest winner was probably Guardiola.
Veteran manager Wenger has always been a believer in clubs not spending "beyond their natural resources" and last week angered Gunners fans by saying there was no way the London side could match the reported £500,000 ($697,000, 569,000 euros) weekly wages on offer to Sanchez at United.
Arsenal and Chelsea renew their rivalry on Wednesday for the fifth time this season, when the stakes are too high, with the first trophy of the season involved. The better team in the Premier League by eight points, Chelsea are [2.62] to win this in 90 minutes with Arsenal [2.98].