TORONTO -- The post-mortem of the past two Toronto Maple Leafs seasons hasn't been pretty. A Game 7 collapse against the Boston Bruins in 2013 gave way to 14-game plunge that cost them a trip to the playoffs in 2014.

Starts haven't been the Leafs' problem. But with an eye on the finish, they hope off-season moves and a competitive training camp can help them write a different kind of ending.

After signing David Booth, Daniel Winnik, Leo Komarov, Petri Kontiola and Mike Santorelli and trading for Matt Frattin, the Leafs have 17 forwards in training camp on one-way NHL contracts. Realistically, only 13 or 14 will make the team following Toronto's most competitive pre-season in recent history.

That's exactly how general manager Dave Nonis likes it.

"We wanted to approach this a different way: There are no spots open, and someone's going to lose their job," Nonis said. "We need the competition in this group to be as high as it's ever been if we're going to maximize the skill level and the talent level that we have."

After losing 12 of the final 14 games last season, the Leafs went through an off-season of change. Brendan Shanahan took over as president, Kyle Dubas and Brandon Pridham joined the front office as assistant GMs, and coach Randy Carlyle got to keep his job but had his assistants replaced.

In terms of roster construction, the core of Phil Kessel, James van Riemsdyk, Joffrey Lupul and captain Dion Phaneuf remains. But after that group wore down as 2013-14 went on, Lupul sees off-season additions as one way to keep history from repeating itself.

"I think that was pretty apparent down the stretch that we didn't quite have the energy it required down the stretch and other teams did," Lupul said. "I think having a little more depth and a little more balance up and down the lineup will certainly help that."

Knowing no NHL team can ever be too deep, Nonis brought in a handful of forwards and defenceman Stephane Robidas in free agency and also traded for Frattin and defenceman Roman Polak to change that tune. His hope was to create a better bottom-six forward group so that Carlyle wouldn't have to keep his stars on the ice for so long.

"If you've got a good third, fourth line you can take away some tough minutes from your top guys and give some rest for Phil, Tyler (Bozak) and James so when we're up by a goal or two goals they don't have to be playing as much as they used to be," Winnik said.

Even as Carlyle talked up a philosophical shift to three scoring lines and a fourth "energy" trio, the next few weeks will determine more than just a few of those spots. There's a competition for the second-line right-winger job, and that's not the only position up for grabs.

David Clarkson, whom Carlyle hopes can hit a "reset" button after a dreadfully disappointing first season with the Leafs, could be given every opportunity to snatch that spot, but first-round pick William Nylander could win it with an impressive showing.

Also in the mix are Booth, Winnik, Komarov, Kontiola, Santorelli, Frattin, Troy Bodie, Colton Orr, Frazer McLaren and Trevor Smith, and there might be eight openings for those 10 players. Nonis wants this camp to resemble the lockout-shortened one in 2013 when players were sent to the minors who might not have been expecting it because of their contract status.

"There's no reason a player should have his spot on the team determined by a one-way contract or the size of his salary," Nonis said. "If we want to have success those players that have higher salaries that are supposed to be our better players have to perform. There's no secret in that. We've made it clear to our players and coaches that all the players need to compete and there's other players that will take their jobs if that doesn't happen."

Carlyle said it's up to him and his staff to pick the right players for those roles. If they choose wisely, it could pay dividends in March and April, the times in which the Leafs have most recently struggled.

"The teams that go deep in the playoffs are playing four lines, they're playing three and a half lines at least," Nonis said. "Injuries as well ... If we have injuries to our top six forwards we think we're in a better position to replace those players and the competition in the lineup from one to probably 13 or 14 up front is as strong as it's ever been."

On defence, veterans Henrik Tallinder and Brendan Mikkelson are in camp on professional tryouts, and one or both lefties could make the team as the Leafs put more priority on balance. Bringing in Polak and Robidas also could have the desired effect of putting less wear and tear on Phaneuf, Morgan Rielly, Jake Gardiner and Cody Franson.

"I think I'd be the first to admit that at the end of maybe game 70 and game 75 you're feeling it when you're playing 27, 28 minutes," Phaneuf said. "I think it will help our whole defensive corps when you have two guys that can play minutes like that."

Notes: Robidas, who broke his right leg while in the playoffs with the Anaheim Ducks, hopes to be in the lineup for the Leafs' regular-season opener Oct. 8 against the Montreal Canadiens. Robidas, 37, who signed a three-year contract on July 1, said he likely wouldn't be able to play in the pre-season until the final couple of games. Nonis said Robidas was on pace in his recovery and had not had a setback. ... Lupul (knee) and goaltender Jonathan Bernier (sports hernia and knee) reported being fully healthy and ready to go for the start of camp. ... The Leafs are scheduled for on-ice testing Friday and have their first practice set for Saturday. Their pre-season opener is Monday in London, Ont., against the Philadelphia Flyers.