Li instead will play a different but still pivotal role within the seven-man council where Beijing's power is centered. As China's presumptive premier, he will be charged with steering its mammoth economy, which is slowing after years of double-digit growth.
Li, currently vice premier, will not officially succeed Premier Wen Jiabao until March, but with Wen out of the leadership lineup announced Thursday, the transition has begun.
Li's relationship with Xi remains ambiguous, although the two are expected to follow the existing model under which Hu stayed somewhat aloof as head of state while Wen acted as the public face of the administration.
Xi and Li, who speaks English and is married to an English professor, are seen as part of a generation of leaders more comfortable with the West than their predecessors, said Ding Xueliang of Hong Kong University of Science and Technology.
"Their reference for great power status from Day One was the United States, unlike Hu Jintao and Wen Jiabao, who looked toward the Soviet Union," Ding said.
Li has been a cautious bureaucrat who rose through, and is bound by, a consensus-oriented Communist Party that has been slow to reform its massive state-owned enterprises while reflexively stifling dissent. He has been an enforcer, keeping a lid on bad news, but has also been able to rapidly reverse course.
He was governor of the agricultural province of Henan in 1998 during an unusual explosion of AIDS cases. Tens of thousands of people had contracted HIV from illegal blood-buying rings that pooled plasma and reinjected it into donors after removing the blood products.
Beijing hadn't acknowledged the problem yet, and Li oversaw a campaign to squelch reporting about it, harass activists and isolate affected villages. When the government finally did go public four years later, Li showed canny political instincts by quickly channeling government assistance to victims and making public shows of compassion.
Li has called for structural reform of China's economy, citing the need for greater balance, coordination and stability. In an April speech to the Boao Forum, a gathering of government officials and business leaders in southern China, he said China wants to create an "open, transparent, fair, competitive, and predictable marketplace and legal environment."
Yet similar pledges have been made many times before, including in China's latest Five Year Plan. Questions remain about Li's willingness to take on vested interests, particularly in the state-owned enterprises, said Patrick Chovanec, a business professor at Beijing's Tsinghua University.
"It remains to be seen whether Li will come out as a leader, or just follow a weak, watered-down consensus," Chovanec said.
That demand for consensus severely constrains the scope of any administrative reform, even though Li and the party say they are necessary, said U.S. Naval Academy China scholar Yu Maochun.
"You can't change the key parts of China's economic structure without fundamentally changing China's political structure, so I don't expect much" from Li, Yu said.
Since his 2007 appointment to the Standing Committee, Li has overseen modest progress in his areas of responsibility, including public health, food safety and housing, which have long been plagued by funding difficulties, lax supervision and soaring prices.
He's maintained a steady, if low-key, schedule of meetings and speeches. A visit last year to the Chinese autonomous region of Hong Kong attracted the greatest attention—though not necessarily for the right reasons.
The stifling security surrounding Li and his unwillingness to meet with political critics seemed to cast him as a typical Chinese leader, tone deaf to public opinion in the former British colony, which maintains political freedoms and its own legal system.
Li has largely steered clear of the webs of corruption surrounding other leading Chinese officials, although questions have been raised over whether his brother's powerful position at the government tobacco monopoly clashes with Li's role in making health policy.
Li's formative years are typical of the fifth generation of communist leaders. He was introduced to politics during the chaotic 1966-76 Cultural Revolution, then entered the prestigious Peking University.
After graduation, Li went to work at the Communist Youth League, an organization that grooms university students for party roles, and at the time was led by Hu.
After serving as Henan governor, Li's next posting was in the northeastern rustbelt province of Liaoning, where he oversaw a revival that drew foreign investment from BMW and Intel.