Ferguson delighted with Rio
Ferdinand has been omitted by England in recent times due to recurring injuries, which have hampered his appearances at club level. However, a turnaround in fortunes has allowed the 33-year-old to return as a leader in United's defence during the climax of the Premier League title race.
"He (Ferdinand) should be okay for another season - he only turns 34 in November," Ferguson said. "We don't train him every day. We let him have the odd quiet day, as we call it.
"He has had to change his game as he got older because he used to rely on his pace and mobility such a lot. He was such a pure athlete, he could outrun anyone, and he used to take advantage of that. He can't do that anymore so he has had to improve his positioning and play a bit deeper.
"Experience is a vital part of his game now. He has done a lot to help Jonny Evans come on so well and he has helped David De Gea settle in.
"He has had a lot of responsibility with Nemanja Vidic being out, but his present form is his most consistent for a long time. In his younger days he would often make the odd mistake through casualness, he had that wee trait in him. Now you don't get any mistakes at all."
Ferguson believes Ferdinand's current form warrants a return to the national team for Euro 2012, adding that his experience will help England during a period of transition in which former boss Fabio Capello has departed.
"If I were England manager, I would take him to the Euros for his experience," Ferguson said. "He and John Terry are the only experienced central defenders England have got. All the rest are young, really. I don't think there are any experienced centre-backs to challenge them, but Rio has not been in the last few squads so it's a decision for the next England manager."
United face QPR on Sunday lunchtime while title rivals Manchester City travel to Arsenal later in the day, and Ferguson is pinning his hopes on the experience of Ferdinand and his team-mates to guide the club to a record 20th league title.
"We have a lot of experience in our team, and the knowledge of players like Ryan Giggs, Paul Scholes, Patrice Evra and Rio Ferdinand will be vital in the coming weeks, but we have also got young lads breaking into the side who are looking at those players and working out what they are doing right to have lasted so long," he said. "They are great examples for young players to learn from."