Bradford manager Peter Taylor was unaware until the player's agent rang him on Friday morning and told him Speight was appearing in court.
Taylor told the Telegraph & Argus: "I'm very disappointed because we were totally unaware this was happening."
"This incident happened in February and Jake and his agent never told anyone that it would go any further.
"That's why I didn't know and Mansfield Town didn't know."
Speight, who joined Bradford from Mansfield two weeks ago, will definitely be unavailable for the opening game of the League Two season at Shrewsbury.
He thought he would get a warning and the outcome has been a nightmare for him
Bradford manager Peter Taylor
He will not be paid by the club while in prison, and could have his wages capped until ready for first-team selection.
Taylor added: "They should have warned me but, to be fair to Jake, his desire to play for Bradford was so strong that he felt he might mess his chances up.
"He thought he would get a warning and the outcome has been a nightmare for him.
"I should have been told but I do understand a little bit why I wasn't."
Speight was brought to Bradford at the end of June on the back of his goal-scoring record of 17 goals in 33 matches for Mansfield Town last season.
Meanwhile there has also been bad news for young midfielder Luke Dean, after it was confirmed that he broke his leg in Friday's friendly win at Eccleshill United.
The 20-year-old is on a short-term contract until January but will be out of action until at least the end of September.
But Taylor is hopeful of bringing another player in on loan before the end of the week.
He told BBC Radio Leeds: "I can't give you any more until it's signed, sealed and delivered in case anyone else fancies him.
"I'm really hopeful we're going to get at least one more, and if that's the case, and everyone stays fit, we'll be near on set for the first game."
Source: BBC Sport
Source: BBC Sport