Leeds, who were promoted to the English top flight after the 2019/20 campaign, were relegated this season after finishing second bottom.
The Yorkshire club were known for their attacking style under former coach Marcelo Bielsa but went through four managerial changes this season, bringing in Sam Allardyce with four games left to play in a bid to beat the drop.
"We have made significant investments to try to keep Leeds United in the Premier League, but in working hard to improve the club, we have also obviously made some mistakes," Radrizzani said in a statement.
"We are reflecting on the decisions that we have taken to ensure we learn the lessons to improve our club and make progress in the future.
"We need a clear strategy to continue our vision for the club and work is underway to produce this which we hope will be reflected in some key appointments in different areas of the club," added Radrizzani, who recently secured a deal to take over Italian club Sampdoria.
