Capitals beat writer Katie Carrera talks with Post Sports Live's Jonathan Forsythe about the challenges coach Adam Oates faces this season and whether Alex Ovechkin could really leave the NHL to play for the KHL's Dynamo Moscow. (Post Sports Live/The Washington Post)

Seventy playerswill step onto the ice Thursday in Arlington for the first practices of Washington Capitals training camp, but the vast majority of the 23 who remain at the end of September will be familiar faces.

General Manager George McPhee didn’t overhaul the roster after last year’s first-round playoff exit — center Mikhail Grabovski was the only significant addition to a group that saw forwards Mike Ribeiro and Matt Hendricks depart as free agents — and 21 of the 27 players who appeared in more than five games last year are back in the fold.

Barring injuries, many returning veterans are all but ensured a spot in the lineup when the Capitals open the season on Oct. 1 in Chicago. But with a handful of prospects and less established players looking to earn more important roles, the 18-day training camp and eight exhibition contests won’t be without battles.

“It’s a good and bad thing,” Coach Adam Oates said. “It’s good that you’ve got depth, but obviously some tough decisions have to happen. Guys are going to be playing for their lives, in a sense. You feel for them when it comes to that, but it’s part of the business.”

The uncertainties start with Tom Wilson, 19, who made his NHL debut last season in three pressure-packed first-round playoff games against the New York Rangers. Wilson will vie to rejoin the Capitals rather than be sent back to the OHL’s Plymouth Whalers.

Wilson is competing for a spot among the bottom six forwards, but it’s doubtful Washington would want the highly-touted winger in the NHL full time if he would see only limited fourth-line minutes, especially when he could be playing more than 20 per game in juniors. Can he push his way onto the third line?

“I think the real question is whether it’s better to take my time and go back and develop a little bit more in Plymouth or make the jump and learn more up here,” Wilson said. “It’s not really my decision. I just have to make their decision tough to send me away.”

If Wilson, the Capitals’ first-round pick in 2012, can earn a spot on the NHL roster this year, it will have a ripple effect. Wilson carries a $1,294,167 salary cap hit. With only $665,705 in cap space available as camp opens, Washington would need to make a roster move in order to bring him aboard.

Wilson’s future will directly impact the configuration of the bottom six forwards, where five players are fighting for three spots: third-line right wing and both the right and left wing on the fourth line. In addition to Wilson, veterans Joel Ward, Eric Fehr, Jason Chimera and Aaron Volpatti are all in the mix to round out those units.

Oates prefers to not have a designated checking line, favoring a third line that is able to contribute offensively and a fourth line that he trusts to handle any situation.

“You want to be able to put anybody on the ice at any time and if you can do it, roll your lines,” Oates said. “The league has really shown the last few years that you need four lines to compete on a day-to-day basis.”

The top half of the lineup is almost entirely set. Oates has said he intends to start with Alex Ovechkin, Nicklas Backstrom and Marcus Johansson together on the top line, as they were for the second half of last season. It’s unclear whether Martin Erat or Brooks Laich, healthy after missing all but nine games last season with a groin injury, will see more time as second-line left wing alongside Grabovski and Troy Brouwer.

The starting spot in net is Braden Holtby’s until proven otherwise, but it will be interesting to see how much game action Michal Neuvirth ultimately receives. Prospect Philipp Grubauer will see the bulk of the workload in Hershey, but could make an appearance if there are injuries in Washington.

Defensively, youngsters Dmitry Orlov and Tomas Kundratek will try to unseat one of the incumbent blue-liners ahead of them on the depth chart.

It’s a critical year for Orlov, 22, as he tries to move to the NHL full time in the final year of his entry-level contract. The hard-hitting left-handed shot would need to outplay John Erskine or Jack Hillen to make it into the lineup.

Kundratek, a right-handed shot, will push Steve Oleksy for a place on the third pairing, but could also make the team as the seventh defenseman.

Oates likes to foster competition, but at the same time respects returning players who previously held a role. That’s why many will begin camp right where they left off last season, but every player still has to earn his spot on the roster.

“A guy that was here at the end will get his spot first, but in saying that, there’s no guarantees,” Oates said. “It’s theirs to lose, and obviously somebody has to upset them.”