"I think he is the one who is the backbone of the team," Rayudu said of the right-hander, who played just 14 matches this season after being laid low by a hand injury.
The 40-year-old Tendulkar announced his retirement last night after Mumbai beat Chennai Super Kings by 23 runs at the Eden Gardens to capture their maiden IPL trophy.
Rayudu said the triumph was a result of four seasons of hard work.
"I think the unbeaten run at home set the tone for the Playoffs," he added.
The MI batsman was also left amazed by the enthusiastic crowd that turned up at the Eden.
"It is unbelievable how a packed Eden Gardens witnessed us. It is a dream. There is nothing better than this," he said.