Arsenal complete deadline day signing of Chelsea's David Luiz

Arsenal have completed the signing of David Luiz from rivals Chelsea on deadline day in England on Thursday after the Brazilian expressed a desire to leave Stamford Bridge this week. 

Luiz, 32, began his career with Benfica and has since played for Chelsea twice, while he also had a spell at Paris Saint-Germain, where he played under Arsenal coach Unai Emery. He has also played 56 times for Brazil. 

"David has a lot of experience and I am looking forward to working with him again," Emery said. "He's a well-known player and he's going to strengthen our defence." 

Arsenal also announced the signing of Scottish left-back Kieran Tierney from Celtic on Thursday.