Borussia Dortmund have already tied up deals for Julian Brandt, Thorgan Hazard and Nico Schulz, but Axel Witsel has hinted that there could be more to come.
He already has plenty of quality on his books in the form of Witsel, Jadon Sancho, Marco Reus and Paco Alcacer.
Reinforcements are required, though, and Dortmund have moved early in the window to get fresh faces on board.
Witsel is impressed with the ambition being shown, but believes that further funds could be invested before the end of the summer.
“I played against Brandt in Leverkusen, it was hard work. I'm delighted for Thorgan, too; he's only going to get better, but they're all good transfers. We need them, and perhaps there are more on the way.”
Witsel said of that experience and how it can serve the club well: “We gave away too many points during the second half of the season, but we're a young team.
“It was still a positive experience because we played a brilliant season. Nobody expected it from us. Now we have to learn from the experience.”
Everyone at Signal Iduna Park is determined to right the wrongs of 2018-19 next season, with Witsel confident that Dortmund will be back in contention for major honours at home and abroad.
He added: “We want to play an even better season next term.
“We've got young players, but experienced guys, too. You need that in a title race.
“We can win titles and cups, anything is possible!”
Witsel returned to European football from China in the summer of 2018 and committed to a four-year contract at Dortmund, with the 30-year-old buying into a long-term project.