PHILADELPHIA — The Philadelphia Eagles have positioned themselves to be big players in free agency when it begins next Tuesday.

On Monday, they sent shock waves through the NFL when they traded star running back LeSean McCoy and his $11.9 million cap number to the Buffalo Bills in exchange for third-year linebacker Kiko Alonso.

They also released cornerback Cary Williams and outside linebacker Trent Cole. Last week, they released veteran right guard Todd Herremans.

The Eagles currently have $43.6 million in cap space. That includes the McCoy trade, even though the deal won’t be official until the first day of the league year on March 10. That’s the fifth most cap room in the league, and it figures to grow some more.

With the acquisition of Alonso, the Eagles are expected to release veteran inside linebacker DeMeco Ryans. The 30-year-old Ryans, who is recovering from his second Achilles tear in five years, has a $6.9 million cap number.

Another Eagles player who could be in jeopardy of being released is 33-year-old All-Pro left guard Evan Mathis, who has a $6.5 million cap number. The Eagles would create another $4.5 million in cap space by cutting him.

The Eagles traditionally have not been big players in free agency. They usually prefer to build through the draft and focus on re-signing their own players rather than overpaying free agents.

“Unless it’s really the right fit for the position, the (right) age, the (right) history of the player, the (right) scheme fit, you want to be careful,” former general manager Howie Roseman said last year before the start of the free agency signing period.

“Because when you talk about these top free agents, you’re tied in for a lot longer than for a year or two. It limits your flexibility. And you’re bringing guys into your locker room that you haven’t drafted and haven’t been in the culture (of your system). Chemistry is a big part of what you’re trying to build.”

But Roseman no longer is in charge. He lost a power struggle to third-year head coach Chip Kelly in early January, and Kelly clearly appears bullish on fixing a lot of the Eagles’ roster problems through free agency.

Their defense is expected to have a minimum of five new starters next season — two new cornerbacks, a new safety alongside Malcolm Jenkins, a new outside linebacker to replace Cole and a new inside linebacker (Alonso replacing Ryans).

The Eagles are believed to be targeting Seattle’s free-agent corner, Byron Maxwell, and New England’s free-agent safety, Devin McCourty. They also have strong interest in Steelers edge rusher Jason Worilds.

The Eagles opted not to use the franchise tag on wide receiver Jeremy Maclin. Maclin led the team in receiving last season with 85 catches, 1,318 yards and 10 touchdowns. It’s unclear whether the Eagles will try to re-sign Maclin after he tests the market or whether they will go in a different direction.