Speaking to Sport Bild, Ricken was emphatic.
"Yes. Absolutely. Without him we wouldn't be in second place, because firstly he has stabilised the squad and secondly he led us into the Champions League last season. Had we not achieved that, it would have had massive consequences for the squad."
The remarks leave no room for ambiguity at a club that has burned through coaches in recent years, with Nuri Sahin lasting barely a season before Kovac was brought in as his replacement in February 2025.
The 54-year-old Croatian took over a Dortmund side that had slumped to 11th in the Bundesliga and immediately set about rebuilding. His record at the club — a points-per-game average of 2.02 — places him among the most successful coaches in Dortmund's history on paper, though his more conservative, defensively disciplined approach has drawn criticism from some supporters who prefer a more expansive style. Ricken was having none of it.
"Niko fits our club wonderfully," he told the magazine, saying he could elaborate at length on why.
The context matters. Dortmund sit second in the Bundesliga this season and are in the Europa League quarter-finals — a significant recovery from the turmoil of early 2025, when the club were mired in mid-table. Kovac has built much of that improvement on defensive solidity, with only Bayern Munich conceding fewer Bundesliga goals at the midpoint of the season.
Questions remain over the futures of key players, including striker Serhou Guirassy, whose €35 million release clause becomes active in July and has attracted interest from clubs across Europe. Whatever happens in the transfer market, Ricken has made clear that Kovac will be the man tasked with building around whatever squad remains.