Bremen pulled a goal back six minutes later after Davie Selke headed Ludwig Augustinsson's pinpoint cross into the area.
After selling Ivan Rakitic to Sevilla, Barca are currently looking to sell striker Luis Suarez, with Juventus a possible destination, while Arturo Vidal is close to joining Inter Milan.
Martinez's call-up came two days after he ended his 10-year spell at Arsenal to join rivals Aston Villa for a reported fee of 20 million euros (around 24 million US dollars).
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.
Much of the pre-match talk has been about the role Martin Odegaard could play after the Norwegian's successful loan spell at Real Sociedad earned him a quick return to the Santiago Bernabeu.
Keno doubled his personal tally with a low finish and then headed in his third goal by latching on to a Mariano cross.
The clash between last season's Premier League and Championship winners was the most eagerly anticipated match of the new campaign's first weekend, and the two sides duly served up a thriller at Anfield.
LONDON, Sept. 16 (Xinhua) -- Arsenal's hopes for the new season have received a major boost with club captain, Pierre-Emerick Aubameyang signing a new three-year contract with the club.
Elhami was banned from coaching activities by the Disciplinary Committee of the Iranian Football Federation.
CONMEBOL says it has imposed strict sanitary protocols for the tournament, in accordance with requirements in each of the confederation's 10 member nations.
Just before the break, Hoffenheim took a 2-1 lead as a VAR-assisted penalty was awarded after Rafael Czichos was fouled inside the box. Kramaric stepped up and slotted home past Horn.