Eight months later, it appears they'll finally get a chance to see him line up at guard in a regular-season game.
Left guard Willie Colon had surgery on his left knee on Monday and could be out for the season. Tomlin said Tuesday that DeCastro will be worked in at right guard during practice this week and could start Sunday when the Steelers (7-6) play at Dallas (7-6).
After quickly earning his way onto the first team, DeCastro sustained a torn MCL during the Steelers' third preseason game and did not return to practice until mid-November. He was in uniform the past two games but only used on special teams.
"We're ready to take the next step," Tomlin said. "Potentially, this week -- depending on how that preparation looks."
In past years, an injury such as the one DeCastro sustained Aug. 25 in Buffalo might have meant a lost rookie season. But with modified injured reserve rules implemented this season, DeCastro was placed on an IR list that allowed him to come back after eight weeks. He did not, however, immediately regain the starting job he won early in camp. The Steelers instead chose to ease him into NFL life.
"With a guy like him, it's more than health because he doesn't have a lot of playing background," Tomlin said. "So although he's been healthy, practice has been good for him, the technique growth and development has been good for him, just simply playing professional football has been good for him. So although he's been healthy, we still thought he had room for growth from an overall readiness standpoint."
Tomlin did not guarantee DeCastro would start Sunday but did make reference to Foster's familiarity with left guard and the preference to return Pouncey to his most comfortable position.
Colon's injury wasn't discovered until Nov. 23, two days before the Steelers played in Cleveland. Colon did not practice the Friday before the Browns game but downplayed it as a routine day off. During pregame warmups in Cleveland, the knee swelled up and he did not play. Colon missed the following week's game at Baltimore but returned to practice late last week before being knocked out of a loss to San Diego this past Sunday.
"He will be out for several weeks," Tomlin said. "I think we need to let a day or two go by before we look at the totality of a possible return."
The injury situation in Pittsburgh's secondary is rough, as well.
Ike Taylor will miss his second consecutive game due to a broken right ankle, and Tomlin revealed Tuesday that Keenan Lewis and Cortez Allen have hip flexor ailments. Although both will be limited in practice, Tomlin indicated he was more optimistic about Lewis' potential availability to play Sunday.
Lewis started in Taylor's place against San Diego, with Curtis Brown filling in as the slot. The result was 12 third-down conversions from San Diego -- the majority targeted at Allen or Brown.
Brown was benched in the second half in favor of the undrafted Josh Victorian. The first-year pro was on the practice squad just last week -- but he could be in line for a significant role in Dallas if either Allen or Lewis can't play. Victorian was beat for a touchdown by Danario Alexander in the fourth quarter Sunday.
Another cornerback who had yet to see many reps on defense but who might be pressed into action is DeMarcus Van Dyke. Van Dyke was cut by Oakland at the end of training camp a year after being drafted in the third round by the Raiders.
"Obviously, we are running short at cornerback," Tomlin said. "Those guys that had the opportunity to step up and log a bunch of snaps over the last week and a half, it looks like that is going to continue."
Van Dyke started four of the 14 games he played for Oakland as a rookie last season. He was active for Pittsburgh's first six games this season. After being flagged five times for fouls on special teams over a three-game span, though, he was benched. He was a Sunday inactive five times in a six-game span before playing vs. the Chargers.
"We will continue to work with those guys and build a plan around what they are capable of executing and executing at a high level," Tomlin said. "More than anything, it's not about what we call; it's about what those guys are capable of executing."