Bayern Munich routed Borussia Monchengladbach 5-1 here in its first Bundesliga game since clinching a 6th consecutive league title.
"It must be a day to celebrate for media and fans with so many highlights", said the 72-year-old coach of the 2018 German champion.
But, there is the risk that their final weeks of the season could see a downturn in form as Kovac's mind begins to shift towards Bayern - who Frankfurt could go up against in the DFB-Pokal final should they win their respective semi-finals.
Salihamidzic said: "We agreed a three-year contract on Thursday. We are convinced he is the right coach for the future of Bayern".
Bayern Munich president Uli Hoeness hit back at Eintracht Frankfurt on Saturday, calling criticism over the hiring of Niko Kovac "rather outrageous".
That was the season in which the German club won the treble under Heynckes and the head coach hopes the fact they have the first leg at home, just as they did in 2013, is a positive sign.
Several high-profile coaches, including Tottenham boss Mauricio Pochettino, were linked with the Bayern job after Heynckes reportedly rejected the offer of a contract extension.
The elder Kovac was also coach of the Croatian team with his brother as assistant manager.
However, the story had already made the headlines the evening before in Germany, and Eintracht sporting director Fredi Bobic accused Bayern of leaking the news, a move he called "annoying, unprofessional and lacking respect".
"We were obviously surprised especially in this phase (of the season) we are in which is extremely important for us", Bobic said.
Eintracht Frankfurt's line-up in 2017/18 based on average position and minutes played.
"Secondly, we thought for a long time about when we should tell the Frankfurters".
But who is set to benefit, and who will lose out on the appointment of Kovac as Bayern's new manager? Champions League qualification is possible this season after another stellar campaign.
This season the Eagles are now fifth in the Bundesliga and fighting for a place in the Champions League for the first time since they were losing finalists to Real Madrid in 1959/60 (when it was the European Cup), just two points behind Bayer Leverkusen in fourth. I informed the team this morning.
How will Bayern line up with Kovac at the helm?