Boris Becker has been welcomed back to German tennis "with open arms", seven weeks after being released from a London prison.
Becker, 55, sat in the team's box during Saturday's Davis Cup loss to Switzerland in the western city of Trier, posting on Instagram on Sunday "we fought hard and left everything on the court".
The six-time Grand Slam champion, and former world number one, served eight months of a two-and-a-half year sentence in England for flouting insolvency rules.
While Becker may have only attended the weekend Davis Cup tie in an unofficial capacity, there is speculation he may return to his former role as Head of Men's Tennis with the German Tennis Association (DTB).
Speaking with tabloid Bild, German number one Alexander Zverev said: "We (German tennis) welcome him with open arms."
Former Davis Cup captain Becker was invited by the DTB as a "friend of the team".
He was seen embracing and consoling players at the end of the tie on Saturday.
"Boris knows how it's done. It doesn't matter whether it's a player, a coach, the DTB or anyone else, he can help everywhere," Zverev said.
Davis Cup teammate Oscar Otte also lauded the presence of Becker.
"He said some really good things to me during the warm-up. That helps enormously," said Otte.
"There's a lot of experience. We're all very happy he's back."
Becker's return comes at a difficult time for German men's tennis.
Former Wimbledon winner Michael Stich told Germany's FAZ newspaper on Sunday "we have the problem that the gap to Zverev is huge, at least in individual terms."
Zverev, a former world number two, is now 14 in the rankings while Otte is at 80 and Daniel Altmaier is ranked at 91.
From 2013 to 2016, Becker coached Novak Djokovic to six of his 22 Grand Slams.