Stating that he was campaigning for the first time, the former Indian football team captain appealed on Wednesday to the Hatia electorate to vote for the AJSU contestant in the presence of party president and Jharkhand deputy chief minister Sudesh Mahto.
Team India Captain Mahendra Singh Dhoni's brother, Narendra Singh Dhoni, was also present during the campaigning.
"We are thankful to Baichung Bhutia for sparing his valuable time for us. We are thrilled. We also thank Narendra Singh Dhoni for campaigning for our party, though he has not joined any party after quitting the Bharatiya Janata Party," AJSU vice-president Praveen Prabhakar told PTI.
The bypoll was necessitated following the death of Congress legislator Gopal Sharan Nath Shahdeo in 2010.
The CBI had on May 18 conducted raids on the premises of 15 MLAs, and four of them belong to the AJSU, including Jharkhand Labour Minister Chandraprakash Choudhary.
The central investigating agency carried out the raids in connection with horse trading allegations that forced the scrapping of the March 30 Rajya Sabha seats for two seats.
The seats were filled up after fresh elections on May 3.