Bremen took the reins from the starting whistle but had to wait until the 18th minute for their first opportunity when Theodor Gebre Selassie rattled the left post from five meters.
Real Madrid, Manchester City and Real Betis have also reportedly shown interest in the defender, whose contract with River expires next June.
The Serie A teams hope that the creation of the yet to be named media company will help boost revenue from broadcast rights, an area where Serie A earns less than rival leagues in England, Germany, and Spain.
AFC said in a separate statement that it had received notification from Al Wahda of United Arab Emirates that the club is unable to travel to Qatar to compete in the AFC Champions League West Zone matches where they currently occupy second place in Group A after several members of the club tested positive for COVID-19.
Sunday kicked off with Christian Tello's 94th minute goal giving Manuel Pellegrini a win in his debut as Betis coach and to ensure Pablo Machin begins his spell in charge at Alaves with a defeat.
"It's all or nothing," Thiem said. "It's going to be a completely open match. I'm really looking forward to that. We have such a great friendship and rivalry. It's amazing that we're going to face each other in a Grand Slam final."
Two minutes later, Bremen eventually broke the deadlock after Ludwig Augustinsson's pinpoint cross to the far post found Joshua Sargent, who made no mistake to head home into the top left corner.
Cheptegei is already the 2019 men's 10,000 world champion and world cross country champion.
"It has been a long time I have not played competitive matches with so many teams, and I am so happy to be back on the pitch again," he said, adding that he will do what he can to help his team win the championship.
The season kicked off with a dull 0-0 draw between Eibar and Celta Vigo and the 90 minutes between two sides that flirted with relegation last season was really only memorable for Eibar's Pape Diop becoming the first player sent off in Spain this season.
Huesca sprang a minor surprise on their return to the top-flight as they took a point away at Villarreal.