After his unexplained two-week absence from the public eye, China's presumptive president-in-waiting looks to be undertaking a campaign to prove he's healthy and fit to lead, starting with a meeting this week with U.S. Secretary of Defense Leon Panetta. Vice President Xi Jinping's tour of China Agricultural University in Beijing Saturday, his first public appearance in more than two weeks, wasn't enough by itself to reinstate the confidence of the Chinese public. His absence became an issue when he missed a few meetings with foreign diplomats, including U.S. Secretary of State Hillary Clinton, so the meeting with Panetta looks like an attempt to make up for that. MarketWatch's Chris Oliver spoke to traders in Hong Kong, who sounded spooked by Xi's unexplained absence. "There’s concern that the handover isn’t going as smoothly as people had hoped it would," one told him. As The Atlantic's Brian Killough pointed out on Friday, "At the very least, there seems to be a national 'loss of face' for missing meetings with foreign dignitaries." Xi's planning not only the Panetta meeting but an appearance at a trade event for the Association of Southeast Asian Nations scheduled for the end of this week. Xi and Panetta are expected to discuss how China and Japan can "peacefully resolve the territory disputes" over a set of islands which is rippling into trade between the two nations, as well as the new missile radar the U.S. has agreed to put in Japan, the Associated Press reports. If he really was out with a bad back, as the most popular rumors of his absence claimed, he's going to need a lot of Advil.