City have mutually agreed to cancel the contract of Sikora to boost his prospects of senior football, with the 19-year-old having made just one first-team appearance this season - against Manchester United under-21s in the Papa John’s Trophy.
Academy graduate Sikora, who signed a one-year contract last summer, spent a spell on loan at non-league outfit Spennymoor Town late last year.
The 19-year-old made six first-team appearances in total for City, stepping out for his League Two debut on the final day of last season against a Morecambe side then managed by Adams.
The Bradford-born player went onto sign a 12-month contract, but has failed to make an impact at first-team level this term.
Sikora said: “I would like to thank everyone at Bradford City who has helped me and been a part of my experience over the past six years, in the academy and first team.
“It was a mutual agreement between the club and I for me to leave, with everything in my best interests and allowing me to play football elsewhere.
“This club has enabled me to fulfil a childhood dream by playing professional football, and I wish it the very best for the future.”
On the incoming front, City have brought in attacking players Jamie Walker and Dion Pereira already this month, with the pair joining on loan from Heart of Midlothian and Luton Town respectively.