Chris Leben announced his retirement following a loss in December to Uriah Hall.

The former Ultimate Fighter competitor battled injuries and drug use throughout his career, losing his last four after a 2011 knockout victory over Wanderlei Silva.

Now, as he looks to make the transition from fighter to another profession, Leben is looking back with a little regret – at least that would seem after a recent post he made on Twitter.

Leben entered the UFC in 2005 after taking part in the first season of TUF. He won his first five fights inside the Octagon before a 2006 knockout loss to Anderson Silva.

The 33-year-old was a semifinalist on TUF, a four-time winner of “Knockout of the Night” honors and the all-time leader in UFC middleweight fights with 22. He also won the WEC middleweight title.

UPDATE: Leben returned to Twitter to try and sort out what he posted, writing, “I love my dog and (expletive) lost it! Sorry please disregard my prev tweet! He was a family member:(”

He posted a picture of the “last minutes of his life. Nothing but love for this little guy. Man’s best friend. You will be missed.”

Leben also appeared to hear from UFC president Dana White concerning the issue, posting, “Means a lot that Dana and the UFC care and have reached out.”