Aston Villa lost 3-1 at Luton Town on Wednesday night.
Roberto Di Matteo has admitted to Aston Villa's official website that he has no idea why his side surrendered in the second half of their abject 3-1 League Cup defeat by Luton Town at Kenilworth Road on Wednesday night.
Aston Villa led through Jordan Ayew on 13 minutes but Jake Gray cancelled out that opener after the half-hour mark as both sides went into the break with one goal apiece.
But it went terribly wrong for Villa after the interval as Cameron McGeehan and an own goal from Jores Okore consigned the Championship side to a first-round exit.
And the Italian manager has admitted that he simply does not know the reasons behind his side's second-half slump, noting that it is "difficult to explain".
Asked by Aston Villa's official website what happened, Di Matteo said: "It’s difficult to explain after a strong team performance in the first half.
"We looked quite compact and difficult for the opposition to break us down. In the second half, suddenly, there wasn’t this team ethic. It’s difficult to explain."
Such an admission by Di Matteo might not sit well with Aston Villa fans, all of whom are looking to him to seal promotion back to the Premier League this season.
This result does not directly affect their promotion hopes, of course, but it does not bode well if the former Chelsea boss - who won the Champions League in 2012 - is already at a loss to explain his side's performances after two matches.
The Villans host Rotherham United on Saturday as they look to bounce back from their 1-0 defeat at Sheffield Wednesday on Sunday evening.