Southend United boss Phil Brown says striker Nile Ranger was dropped from the squad for Tuesday's match at MK Dons after a "disciplinary procedure".
The League One club gave no further details, but Ranger wrote on Twitter: "Have to work on my time keeping".
The 26-year-old was released from prison in August having served 10 weeks for online banking fraud.
He missed Southend's League One game with Shrewsbury in September because of a curfew on his electronic tag.
"Nile isn't involved because of a disciplinary procedure," Brown told BBC Essex before their 1-1 draw.
"It's not for public consumption what's happened but it's just down to discipline and we'll leave it at that."
After the match former Newcastle and Swindon forward Ranger congratulated his team-mates on their performance on Twitter.
Brown was not prepared to elaborate on the issue after the game, but hinted there were other reasons for leaving Ranger out.
"He's scored one goal in 11 games and that was a penalty, simple as that."
The ex-Hull manager was angry with his side's performance at Stadium MK, with a missed penalty costing the Shrimpers points for the second game running and leaving them 14th in League One.
"We've got a penalty policy now - a penalty policy was named before the game and he's [Josh Wright] gone and missed it again, so that's a great policy isn't it," Brown added.
"I was disgusted with it, absolutely disgusted - you can't put chances on a plate like we've done and not take them.
"I can't keep on making changes can I? The only thing we need to change is the mentality."