ORLANDO, Fla. - Tommy Redding has been touted as a defensive prospect for the US national team, and his next step on that particular road is with Orlando City SC.

The Lions travel to the Chicago Fire on Sunday (4 pm ET, UniMás) without regular center back David Mateos, and Redding is firmly in the frame for a role in keeping the team’s MLS Cup playoff hopes alive under new head coach Jason Kreis.

The 19-year-old Homegrown product started the season as a central defensive fixture under former manager Adrian Heath, but has been sidelined twice by injury, first by a concussion against Portland in May and then a serious hamstring injury last month that has kept him out for the past six games.

Now, with Redding back in full training once again, Kreis has his eyes on both the budding US Under-20 star and Uruguayan transfer window capture Jose Aja as the players to step up and eradicate the defensive deficiencies that have periodically undermined Orlando’s campaign so far this year.

One of them is certain to replace the suspended Mateos, but Kreis intimated that he may well find a place for both in Chicago, and start the first major step in rebuilding the team’s suspect back line.

“I think we are a little undecided [over which of the two to play in central defense],” Kreis explained on Friday morning. “The other thing we could look to do is play Tommy at right back, and use both of those players. But we’re undecided right now and probably won’t make a decision until tomorrow afternoon.”

The lingering doubt for Kreis, who took over on July 19, is the lack of any significant first-hand insight on the playing form of the young defensive duo. Aja, 23, has yet to step foot on an MLS field while Kreis has seen Redding in full training for barely two weeks.

“No, I haven’t seen either one of them play in a real match,” the head coach said. “Having said that, I saw Tommy play in the B team match last weekend, so I would consider that an important first step. But I wouldn’t want to be making evaluations about players until we have seen them in MLS matches.

“I think they both have potential to be something quite nice [in this league] from what I have seen so far. I am certainly very interested to see what it looks like to see them play MLS matches.”

Kreis is well aware of Redding’s burgeoning reputation at the youth international level, as well as his promising – but limited – MLS work to date from watching game film of this season, and he is intrigued to get his own view of the player at work where it matters most.

“I see a young, potential top, top central defender in MLS based on the performances he had before he was injured,” Kreis said. “Hence we will take a very interested view in trying to help him develop to take the next step and reach the next level, which for him, the immediate next level is a regular MLS starting place.”

It is Redding’s all-round athleticism, packed into a powerful 6-foot-1 frame, that potentially gives him the edge over Orlando’s other defensive options, and Kreis is quick to acknowledge the fact.

“That would definitely put him in a different position to the others as we’re looking for what particular players can bring that the others can’t.” he said. “For Tommy, I would say his athleticism is an attribute that he can bring that perhaps the others don’t quite have yet.”

With Redding likely inching his way back into the starting spotlight, Kreis is also anxious to see if another week of focus on the defensive third will yield dividends following the disappointing display in last Sunday’s 3-1 defeat to Seattle that handed the Lions their first home loss in more than a year.

“That is 100 percent the focus this week,” he insisted. “I am seeing [an improvement] in the training sessions, but ultimately as we as we all know, the most important performances are the matches. And we need to see the learning happening in the matches.”