Marko Grujic says he returned to Hertha Berlin for a second season of Bundesliga football on the advice of Liverpool coach Jürgen Klopp.
Grujic, 23, produced five goals and one assist in 20 Bundesliga appearances during his first loan spell with Hertha last season, before briefly heading back to Liverpool in the summer.
"I spent a few days in Liverpool for medical tests at the end of the season," Grujic told Sport Bild. "We sat down together and talked about my plans.
"I have a contract with Liverpool until 2023, but we had a similar view: I was only able to call on 50 per cent of my abilities at Hertha. Niggling injuries set me back.
"He thought, and I agreed, it would be better for my development to spend another year in the Bundesliga."
Watch: Marko Grujic reflects on his first goals in the Bundesliga and life at Hertha Berlin
Grujic also revealed Ante Covic's appointment as Hertha head coach played a key role in his decision to stick with the capital club, rather than accept an offer from elsewhere in Germany.
"Ante was the first person at Hertha to get in touch last summer," Grujic said of Hertha's former reserve-team coach. "He explained what Hertha have planned for me and how I can make the most of my potential here.
"He was also a big reason why I really wanted to stay this summer.
"I'm really happy that he's now my coach."
Hertha finished 11th in the Bundesliga last season under Covic's predecessor, Pal Dardai, but Grujic believes the club should be aiming for at least a top-half finish in 2019/20.
"We can achieve more," he said, Hertha having fallen eight points short of a top-half finish in 2018/19.
"We're capable of finishing in and around the top seven.
"It's another reason why I didn't want to leave. I have unfinished business at Hertha."