The Lions filled their initial practice squad Sunday with 10 players who spent time with the team this summer.

The group’s members are offensive tackle Michael Williams, running back George Winn, offensive lineman Rodney Austin, wide receiver Andrew Peacock, tight end Jordan Thompson, defensive tackle Xavier Proctor, cornerback Mohammed Seisay, fullback Emil Igwenagu, safety Nate Ness and linebacker Julian Stanford.

As always, the practice squad is a fluid group whose members could change at the drop of a hat. If the Lions suffer an injury, they could promote someone from the practice squad to the active roster, which is why they have such a diversity of positions.

Practice squad players can also be signed to another team’s active roster at any time. Last year, Austin had an offer from the Tennessee Titans, but the Lions added him to their 53-man roster to avoid losing the versatile interior lineman.

Lions return man Jeremy Ross, for instance, started on the Lions’ practice squad last year after the Green Bay Packers cut him, but he was the primary return man for most of the second half of 2013.

Williams, a seventh-round pick in 2013, impressed this offseason while transitioning from tight end and showed an ability to play on either side. However, undrafted rookie Cornelius Lucas edged him out for the final tackle spot on the 53-man roster.

Winn made the group after a strong offseason in which he consistently showed an ability to run with power. A Southfield native, Winn spent his rookie season with six different teams, but has, for the time being, landed with his hometown team.

Peacock, an undrafted rookie from Appalachian State, was the first player to announce that he was a part of the group.

“Practice squad it is,” he wrote on Twitter. “Happy to still be a Lion! Time to keep working and take full advantage of this!”

The 5-foot-9 Peacock played well in training camp and had eight catches for 74 yards in the exhibition games.

Ness had two interceptions in the exhibition season, and Seisay had one, too. Seisay, an undrafted rookie from Nebraska, outplayed fellow cornerbacks Jonte Green and Chris Greenwood, who were both waived, in the exhibition games to earn a spot on the practice squad.

Igwenagu is effectively a backup fullback and insurance for Jed Collins, who made the 53-man roster.

Stanford joined the Lions late last season and played well on special teams after linebacker Travis Lewis was suspended four games for breaking the league’s performance enhancing drug policy.

Proctor is on the Lions’ practice squad for the second year in a row.