Shamarko Thomas remains behind Will Allen on the Steelers depth chart

It was a disastrous preseason for Shamarko Thomas.

Drafted in the fourth round of the 2013 draft, Thomas has waited in the wings for the past two years, cutting his teeth on special teams. It was a nearly universal assumption among coaches and fans that this would be the year that Thomas would step into the role vacated by strong safety and franchise-legend Troy Polamalu.

As things now appear, though, this isn't likely to be the case--not anytime soon at least.

In his weekly press conference on Tueaday, Head Coach Mike Tomlin confirmed that Thomas won't regain his staring role this Sunday against the San Francisco 49ers. "He’s got to be good above the neck, he’s got to be in a position to make plays and he’s got to be good at communication," said Tomlin, "some things we thought Will Allen gave us a better opportunity to do well at. And, of course, his experience."

Thomas is also listed behind veteran Will Allen on the depth chart, an order that doesn't seem likely to change in the immediate future.

Routinely exposed in coverage during preseason, Thomas gave up a string of big plays and looked completely unprepared to start, especially as the Steelers shift to more two-deep safety looks.

To illustrate just how far Thomas has fallen in the pecking order, former undrafted free agent Robert Golden, a hitherto special teams player only, took his place in specific sub packages that required three safeties on the field, playing 24 snaps on defense to Thomas' four.

It's certainly not yet time to give up on Thomas, since he's a supremely gifted athlete who, because of injuries and competition from incumbent starters, has had precious little playing time. However, it's a long a way back, and this season will be as much a test of his mental fortitude as his skill set.

The Steelers could really use some youth and potential on the back-end of their defense, not too mention some playmaking ability. But only time will tell if Shamarko Thomas will be that man.