EDEN PRAIRIE, Minn. —The Vikings held the first of three mandatory minicamp practices on Tuesday morning at Winter Park.

The session wasn't quite 90 minutes as it was cut short when inclement weather moved in. The Vikings practiced in helmets and shorts in cloudy weather.

The Vikings will hold two more minicamp practices this week before getting some time off before training camp, which opens on July 28 in Mankato.

Here are three observations from Tuesday's session:

1. Ground and pound

With offseason practices limited by non-contact rules, it's tough to gauge the success of the Vikings running game. But that phase of the offense is still a big part of the Vikings identity, and was an element Minnesota focused on Tuesday morning. A substantial amount of team drills consisted of running plays centered around running backs Adrian Peterson, Jerick McKinnon and Matt Asiata.

2. Plug and play

Veteran offensive lineman Joe Berger has played both center and guard in his career. With left guard Alex Boone not participating in Tuesday's practice, Berger stepped up and filled in at that spot with the first team. Berger started all 17 games at center last season, including the playoff game, and was named Pro Football Focus' top-rated run blocker.

3. Stave third in line at QB

Joel Stave was the first quarterback that took reps with the third team offense on Tuesday. Teddy Bridgewater ran with the first team, and Shaun Hill was under center with the next group. Stave was next in line, although quarterback Taylor Heinicke also jumped in for a few reps of his own.