The Oakland Raiders are planning to release offensive tackle Austin Howard on Friday, a source told ESPN's Adam Schefter.

Early on Friday morning, Howard posted on Instagram that he was "grateful" for his three seasons with the team.

Howard has started 39 games over the last three seasons for the Raiders.

He joined Oakland in 2014, signing a five-year, $30 million deal that included $15 million guaranteed. He played for the Jets from 2011 to 2013.