From 2012 to 2015, the Flyers had 13 picks in the first three rounds and used six of them on defensemen, including first-round picks in 2013, 2014 and 2015. Shayne Gostisbehere, a third-round pick (No. 78) in the 2012 NHL Draft, was the first to arrive in the NHL on a full-time basis last season and was the Calder Trophy runner-up with 46 points in 64 games. More talent could be arriving as early as this season.

The Philadelphia Flyers' focus on rebuilding their defense through the draft is close to paying off.

NHL.com is providing in-depth prospect analysis for each of its 30 teams throughout August. Today, the Philadelphia Flyers.

Flyers 30 in 30: Season outlook | Burning questions, reasons for optimism | Fantasy outlook

Here are the Flyers' top five prospects, according to NHL.com:

1. Ivan Provorov, D

How acquired: Selected with No. 7 pick of 2015 NHL Draft

Last season: Brandon (WHL): 62 GP, 21-52-73

There were scouts who believed Provorov was NHL-ready last season, but the Flyers opted to have him spend 2015-16 with Brandon of the Western Hockey League. He led WHL defensemen in points, was third in goals, his plus-64 rating led the league and was the best by a WHL defenseman since 2008-09, and he was voted the top defenseman in the Canadian Hockey League. Provorov had 13 points in 21 WHL playoff games to help Brandon win the championship and advance to the Memorial Cup, and he had eight assists in seven games to help Russia win the silver medal at the 2016 IIHF World Junior Championship.

Provorov (6-foot-1, 201 pounds) is 19, and the Flyers have been hesitant to rush young players to the NHL, meaning there's a chance he'll return to Brandon for another season. But Gostisbehere's play last season showed what a talented young defenseman can bring to a team.

"He's really smart, he reads the game. [It's] really hard to play against him," said Flyers forward prospect Radel Fazleev, who has played against Provorov with Calgary of the WHL the past two seasons and with him at the WJC. "He's a really good defender, good skater. You have to make almost an unreal play to beat him. If you go 1-on-1, if you make a play when he's on you, it's good for you. Just super hard to play against him."

Projected NHL arrival: This season

2. Travis Konecny, C

How acquired: Selected with No. 24 pick of 2015 NHL Draft

Last season: Ottawa (OHL): 29 GP, 7-38-45; Sarnia (OHL): 31 GP, 23-33-56

Konecny said during Flyers development camp that he's added about nine pounds to his 5-10 frame (up to 175). Additional strength and size might be the only thing separating Konecny from an NHL spot. Last season, he had 30 goals and was tied for seventh in the Ontario Hockey League with 101 points in 60 games.

The Flyers were 22nd in the NHL at 2.57 goals per game last season and could use more offense. Konecny will get a long look at training camp, but it's likely the 19-year-old will return to Sarnia for another season of development.

Projected NHL arrival: Next season

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3. Travis Sanheim, D

How acquired: Selected with No. 17 pick of 2014 NHL Draft

Last season: Calgary (WHL): 52 GP, 15-53-68; Lehigh Valley (AHL): 4 GP, 1-2-3

Sanheim, 20, was fourth among WHL defensemen in points last season and made his professional debut before it was over.

The Flyers like the strength Sanheim has added since being drafted, with general manager Ron Hextall saying during development camp that Sanheim (6-3, 181) has added about 25 pounds since he was drafted.

Projected NHL arrival: 2018-19

4. Samuel Morin, D

How acquired: Selected with No. 11 pick of 2013 NHL Draft

Last season: Lehigh Valley (AHL): 76 GP, 4-15-19

Morin, 21, showed some offensive skill and a physical presence in his first professional season; his 118 penalty minutes led Lehigh Valley. He had surgery on his left hip after the season and returned to the ice during development camp.

Morin (6-6, 202), can get stronger, which likely means another season in the American Hockey League. He projects to be a physical defenseman who can chip in with some offense.

Projected NHL arrival: Next season

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5. Robert Hagg, D

How acquired: Selected with No. 41 pick of 2013 NHL Draft

Last season: Lehigh Valley (AHL): 65 GP, 5-6-11

Hagg (6-2, 204) told CSNPhilly.com that an oblique injury sustained early in the season bothered him, and it wasn't until the final two months of 2015-16 that he finally felt like himself.

The 21-year-old projects into a solid second- or third-pair defenseman. He'll likely start the season in the AHL but could be an early call-up option if there's an NHL injury.

Projected NHL arrival: Next season