Radrizzani outlined his plans for Leeds by promising to create “a modern structure, a modern club” at his first press conference since investing at Elland Road this morning.
The 42-year-old Italian finalised a co-ownership deal with Massimo Cellino in December, ending seven months of negotiations to buy into the club.
He and Cellino appeared together alongside each other at a press conference at Elland Road this morning, less than 24 hours after a rousing 1-0 win over Derby County moved Leeds to third in the Championship table.
Radrizzani said: “I’m honoured to have the opportunity here and I’m grateful to Massimo for giving me the opportunity. This club has been unlucky with roller-coaster experiences and different owners in the last decade so the first objective in my ownership and management will definitely be to bring more stability to the club.
“I’ll bring this club (forward) gradually to be a modern structure, a modern club and be ready for when we are back in the top league.”
Cellino admitted that a split of authority would be a “new experience” for him.
But Radrizzani, who built his reputation selling sports media rights, said he had no problem with sharing decisions.
“So far we never had any issues to decide,” he said.
“Since May, even though I wasn’t a shareholder of the club, he always involved me in any important decisions about the building of the team. He was really fair to me in this period. Until now we never had a problem.
“Now we really are partners so we will start to have different agendas and discussions about the progression of the club in the future but we can easily manage Leeds together if we give responsibility and delegate to the management. We have a good team here.
“From the beginning it was clear to me that Massimo didn’t want to sell the club entirely. He has strong passion for Leeds and he’s a fighter. He wants to do something good for the club before he gives up. He would never give up the club.
“We found a way to start together and hopefully to continue together. For me it’s a perfect solution because I have time to learn about the club and football gradually, not in a rush. I start now and I have time to learn and be ready for next season.”
Cellino added that Radrizzani's involvement would help the club become sustainable in the long term.
The Italian said: “It was the right time to take someone on board, someone who comes from my country. If we have to fight we fight better in Italian!
“This is the best thing I could do for the club because the numbers in the Championship are a little bit scary. It takes a lot of money to fix this club. With two owners maybe it’s easier to do it than by myself.
“Andrea has good experience in marketing, televised business and he’s got a good background. He’s 20 years (younger) than me. That’s important because I’m getting a little bit old. For us he gives a longer future than you have with me.”
Cellino has had a controversial time as chairman since first buying a majority share in Leeds in April 2014.
The club's form this season, however, has given the Whites a serious chance of rejoining the Premier League for the first since their relegation in 2004.
Leeds’ win over Derby strengthened their hold on a play-off position and also put the club in contention for a top-two finish, midway through the January transfer window.
Monk said after the game that he was looking for two signings this month to give his squad the “best chance” during the Championship run-in.
Asked about transfers, Cellino admitted he had told Radrizzani not to invest immediate funds for players, saying: “I don’t let him invest nothing yet. We are 50-50. I told him ‘don’t spend nothing.’
“We have many players. Don’t get in a mess. Sometimes we want to have too much. As owners we want to participate in games and sometimes it’s a disaster. The team is playing good, they’re growing. They should get better and better. Sometimes buying players, you think it makes a team stronger but maybe we break it up. Sometimes spending money can hurt the club.”
Radrizzani said: “We are aligned completely, me, Massimo and Garry on what we need. We don’t want to touch the balance of the team. The performance on the pitch and also inside the locker room, everything is working really well. We are looking at potentially one or two players who Garry mentioned. We’re working on that.”