It’s been an extremely busy day for Arsenal.It started with confirmation of Pierre-Emerick Aubameyang’s arrival in a £56 million deal from Borussia Dortmund.The Gabon international has penned a contract at the Emirates Stadium worth £180,000-per-week, marking a nice piece of business from Arsene Wenger.And the good news kept on coming, with BBC Sport’s reliable correspondent David Ornstein reporting that Mesut Ozil has signed a three-and-a-half year contract extension at the club.It brings speculation that Ozil could leave Arsenal on a free transfer in the summer to an end, with the German playmaker putting pen to paper on a deal worth a stunning £350,000-per-week.All of a sudden, Arsenal supporters had forgotten about the 3-1 defeat to Swansea City.

Giroud has signed for Chelsea

But Arsenal have made a habit of selling players to their rivals and the euphoria that surfaced with the Aubameyang deal was punctured somewhat by Olivier Giroud’s move to Chelsea.

The Frenchman has sealed his move to Stamford Bridge in a deal worth £15.3m, with £2.2m in bonuses.

Giroud has signed an 18-month contract at Chelsea.

Thierry Henry has reacted to Giroud transfer

Despite Aubameyang’s signing, many Arsenal supporters are sad to see Giroud leave.

And that includes Gunners legend Thierry Henry, who understands just why Giroud has left the Gunners.

“We all knew it was going to be a matter of when with the domino effect with Aubameyang,” Henry said on Sky Sports this afternoon. “It allowed Giroud to go.

“It’s a weird one because you could feel yesterday when he clapped the Arsenal fans [after the 3-1 defeat at Swansea City], there was something there in him.

"I thought he did what he had to do for Arsenal. He knew Chelsea was coming for him and they’re ahead of Arsenal. Arsene [Wenger] is not playing you…[Alexandre] Lacazette is in front of you."

Henry added: “I cannot fault him or be upset with him for going to Chelsea when he’s not playing for Arsenal.

“The way he likes to play suits Antonio Conte’s football, he likes a target man with a brain. I wish him all the best but Arsenal have lost a great support player.”

Chelsea were linked with Peter Crouch and Andy Carroll but Henry believes Giroud should have been their number one target all along.

“He should have been their first target,” the former striker continued. “Maybe they didn’t think it could happen but then he became available.

“He’s got experience in the league, he can hold the ball, is he going to be alongside [Alvaro] Morata? I don’t know, but now they have two options.”