The 26-year-old leaves Barca after 124 first team appearances in the three years since he joined them from Portuguese giants Benfica.
The winner of this tie will then play away from home against the winner of the game between Swedish team Malmo and the Croatian side Lokomotiva Zagreb. Enditem
Prior to the game, both sides needed a victory to secure them a top four berth with only two games left in the Suzhou division.
Guoan suffered criticism after earlier fumbling a 3-0 lead against Qingdao, suffering instead a 3-3 tie in the first leg.
The 24-time Norway international follows Josep Martinez, Hee-Chan Hwang, Benjamin Henrichs, Lazar Samardzic and Angelino as the sixth new arrival of the summer transfer period.
There should be goals when Sheffield United face Leeds United in Sunday's Yorkshire derby, which could be a baptism of fire for Leeds' new signing Diego Llorente given that his side has scored seven times and conceded the same number in their first two games of the campaign.
Meanwhile, Sport Recife continued their impressive recent form with a 1-0 home victory over Fluminense. Former Flamengo striker Hernane scored from the penalty spot after Leandro Barcia was brought down by Egidio Pereira.
The UAE Team Emirates rider, who will turn 22 on Monday, became the first Slovenian to win the world's elite road cycling event. Meanwhile, the rookie also claimed the polka dot king of the mountains jersey and the best U-26 rider's white jersey.
Other matches on Wednesday saw Shandong smashed Sichuan 3-0 (25-13, 25-17, 25-17), Fujian beat Beijing 3-1 (28-26, 28-26, 19-25, 25-10), Zhejiang edged Guangdong 3-2 (25-20, 25-13, 22-25, 22-25, 18-16), and Liaoning overcame Henan 3-2 (20-25, 24-26, 25-10, 25-11, 15-6). Enditem
A month has passed since then and the game will be a good test of Liverpool's ability to defend their title after beating Chelsea a week ago and also of how much Arsenal have improved under Mikel Arteta. Enditem
The 18-year-old will travel to France this week to undergo a medical and finalize contractual formalities, the Globo Esporte news portal said on Monday. It added that the deal exceeded 10 million euros (12 million U.S. dollars).