Ferguson retires after Sunday's trip to West Brom but he was very much in charge for Monday night's trophy parade from Old Trafford into the centre of Manchester.
The 71-year-old spoke to the thousands who gathered to watch the bus leave, setting his players a challenge they last achieved between 2007 and 2009.
"We have a young squad, with a lot of good young players, who are going to get better," he said.
"The big test is to win it three times in a row.
"I hope the boys can do it."
"Yesterday was a day I will never forget," he said. "I thank you for that."
Ferguson also urged supporters to turn up for Tuesday's Under-21 encounter with Liverpool at Old Trafford.
"We play that mob across the road," he said.
"I hope some of you cheer the young lads on."
Sir Matt Busby Way had to be closed as it reached its 20,000 capacity as the awful rain that belted down in the hours prior to the parade eased off.
Indeed, blue sky appeared for the send off, with Rio Ferdinand and Ashley Young leading the singing, including a tribute for Robin van Persie.
"It feels amazing," said the Dutchman, who is also virtually certain to win the Premier League Golden Boot.
"It has been an unbelievable experience. It has been worth the wait. I have loved every single bit."
Wayne Rooney was also on the bus.
He did not answer directly a question about what the retiring Ferguson had done for him, and was not asked whether he would be staying or not.
"He has been brilliant for us all," said Rooney.
"He is a great manager. He is a winner and to do it for so long is incredible.
"He is a fantastic manager and a fantastic person."
Even Ferguson joined in the singing from the bus. Ryan Giggs, who has played a part in virtually all the Scot's 38 trophies, was delighted United managed to provide a fitting send-off.
"It has been tough, especially for the players who have known him for a long time," said Giggs.
"We are delighted that we were able to end on a high and won the league in his last season."
Coach Rene Meulensteen said he had never known an atmosphere like the one he experienced at Old Trafford on Sunday.
"After Rio got his winner, I have never seen Old Trafford like that," he said.
"It was an unbelievable experience."
Meanwhile Northern Ireland defender Jonny Evans was embarrassed by his fiancee, MUTV reporter Helen McConnell, who was asking questions on the bus.
"Are you going to have a good summer?" she asked.
"Yes," replied Evans. "I am getting married to you Helen."
Van Persie clearly relished his first experience of being a league champion and claimed he had not removed his medal since Sunday's ceremony.
"It is incredible, much nicer than I expected," he said.
"The medal has not left my neck since yesterday.
"It has been a really good year. The boys have been fantastic since day one.
"They want to share success. I want to have success but I want everyone to have success. Everyone plays their part."