The 26-year-old leaves Barca after 124 first team appearances in the three years since he joined them from Portuguese giants Benfica.
Dortmund continued on the front foot and controlled possession but Augsburg's well-positioned defense defused most attacks in the midfield.
Roberto Lopez sealed the win in the 94th minute with a powerful shot into the corner after another assist from the impressive Merino.
The 27-year-old joined Juventus from Real Madrid in 2014. During his two-season spell with the Old Lady, the Spaniard scored 27 goals in 93 outings and won five trophies, including two Scudetti and two Italian Cups.
Without Kun Aguero, Aymeric Laporte and Ilkay Gundogan, who has been diagnosed with the coronavirus, Pep Guardiola handed a debut to recent arrival Nathan Ake, and young phenom Phil Foden was also in the starting 11.
Betis are another team with two wins from two games after Nabil Fekir's penalty after 10 minutes and William Caravalho's powerful drive from outside the area eight minutes later gave the team from Seville a comfortable 2-0 victory against Valladolid and maintain new coach Manuel Pellegrini's perfect start.
POAK finished second in Greece last season and a week ago defeated Portuguese giants Benfica 2-0 to book a place in the qualifying round ahead of the group stage of the Champions League.
The following fixtures are scheduled for Saturday: Borussia Monchengladbach host Union Berlin, Bayer Leverkusen face Leipzig, Mainz meet newly-promoted Stuttgart, Augsburg clash with Borussia Dortmund, newly-promoted Arminia Bielefeld take on Cologne, and Schalke face Werder Bremen. Enditem
"For me and my national team mate Gong Xiangyu, this is our first time to compete in the Chinese Women's Volleyball Championship. Of course we want to deliver our best performance here," said Jiangsu captain Zhang Changning.
Andre Silva (3rd L) of Frankfurt takes a scoring penalty kick during a German Bundesliga match between Hertha BSC and Eintracht Frankfurt in Berlin, capital of Germany, Sept. 25, 2020. (Photo by Kevin Voigt/Xinhua)
Leandro Martinez gave the hosts hope by combining with Cristian Colman and beating goalkeeper Cesar at his near post after some sloppy Flamengo defending.