The Gunners have finalized their squad with two interesting transfers, including a player from one of their bitter rivals.

Arsenal fans have reasons to believe in their chances to make some noise in the upcoming Premier League season, as the Gunners were one of the most active teams on Transfer Deadline Day.

Unai Emery's side rounded up a qualified squad that will try to return to the UEFA Champions League by the end of the season with two signings,as left back Kieran Tierney and David Luiz completed their moves to the Emirates after the summer transfer window was shut down.

The former Celtic player was handed the No.3 jersey as he completed his move during the final moments of the window, and did not hesitate to share a curious anechdote that led to his transfer.

"I got told at seven o'clock last night that I had to be at the airport in an hour, so I had to go quickly. I was actually down the park with my friends training. They play with their local team so I was down watching them and I got a phone call that I needed to go," Tierney told Arsenal's website.

Here's how the club revealed his signing on social media.

But then, the Gunners completed one more transfer that was on the works since late Wednesday, as David Luiz was also unveiled as a new Arsenal player.

Fears about the deal about to fall through circled the air, as neither Chelsea nor Arsenal gave word on this matter when the transfer window shut down. Nevertheless, Arsenal was able to complete the move since they had submitted all paperwork related to this deal.

The Gunners' new No. 23 will team up once again with Unai Emery after their time together at PSG.

While terms of Kieran Tierney's deal were not revealed, David Luiz will join the Gunners after Chelsea and Arsenal agreed an $8.5M fee for the 32-year-old's transfer.