NFL training camps are open, and for millions of people worldwide their fantasy football preparation has begun in earnest. Here at Sports World News we will break down all 32 NFL teams in terms of their fantasy value. Readers will find the must-own players in every format, the sleepers in specific formats, and hidden gems only necessary for those in very deep leagues.

Today's preview will be on the Detroit Lions.

Must Own

Calvin Johnson, WR: Megatron is hands down the No.1 wide receiver in the NFL, and a solid No. 1 overall pick in PPR leagues. His receptions were down last year (from 122 so don't be too hard on him), but he adjusted his touchdowns in a big way. After falling down on the one-yard line an inordinate amount in 2012, Calvin notched 12 TDs in just 14 games last year. He's a lock to have a bunch of catches, a bunch of yards and heaps of touchdowns.

Reggie Bush, RB: ADP suggests Reggie Bush is the horse fantasy owners are betting on to take the lead in the Lions' running back platoon. He's been reliable for 215-225 carries, five-to six scores, and 1,000 yards since joining the team and he's a home run threat in the passing game. The panic about his decreasing role is overblown-Bush will produce. He can even be an RB1 if your wide receiver/tight end situation is loaded enough.

Matthew Stafford, QB: Stafford is possibly the most frustrating player in fantasy. The talent is immense, his yardage is awesome, and the attempts are always there. But after a 41-touchdown breakout in 2011 he's thrown 20 and 29 touchdowns, and limited the impact of those scores with 17 and 19 interceptions. Sometimes it's hard not to look at his situation and arm and weaponry and pick him in Round 4, but it's too early. There are solid quarterbacks going after him that have a very good chance of outproducing him.

Joique Bell, RB: Bell got a career-high 166 carries and rewarded Detroit's faith in him with eight touchdowns. His 3.9 yards per carry isn't overly impressive, but he's a true three-down back. If Bush gets banged up, Bell doesn't have to be replaced on passing downs-in fact, he had 3.3 catches per game last season even with Bush healthy.

Golden Tate, WR: Tate's been overlooked since entering the NFL, and his current ADP of 76th overall, and 31st among wide receivers continues the disrespect. He's a high-quality receiver who was productive in a run-heavy offense in Seattle. He served as a de facto No. 1 last year with Percy Harvin missing almost the whole season and came up with five touchdowns and 898 yards. His touchdowns may not rise much, but his yards and receptions will go up.

Sleepers (Best format)

Brandon Pettigrew, TE (PPR): Pettigrew's been pretty disappointing in terms of what expectations have been for him previously, but overall he's a fairly solid TE. The idea of him ascending into the Top 3 of his position is gone by the wayside, but it's not a horrible idea to punt the position until the end and snag him late.

Eric Ebron, TE (Standard): Detroit seems to be taking things slow with Ebron, who is currently listed as the No. 3 TE on the depth chart. Aside from Calvin Johnson though, Ebron might be the most gifted athlete on the team. His ceiling is Jimmy Graham-that's no joke. Take a flier late.

Deep Finds (Best format)

Theo Riddick, RB (PPR): Riddick has drawn rave reviews in training camp, and although he's small, he has major playmaking ability. He may get an opportunity to play as a kick returner in the early going, but don't be shocked if he starts seeing some snaps in the backfield eventually.