For more than a century, National Football League owners have been an exclusive club. With rules that place tough restrictions on who is allowed to buy teams — and how those purchases can be financed — only the extremely wealthy can afford to join. Now they’re on the cusp of admitting a new kind of member.

At a meeting next week in Eagan, Minn., N.F.L. owners are expected to approve rules that would allow certain private equity firms to buy as much as 10 percent of a team.

The move would help owners solve a liquidity problem. As team valuations have soared — the Washington Commanders sold for $6.05 billion last year — the number of potential buyers has fallen. Finding limited partners has also become more difficult because they have no voting rights yet must tie up tens and even hundreds of millions of dollars. Allowing investments from private equity could make it easier to put together a deal.

The N.F.L. would be the last major sports league to allow private equity firms to become minority owners, and its approach is more conservative than leagues like the National Basketball Association, which allows private equity firms to own up to 30 percent of a team. If the new rules pass, only a handful of anointed private equity firms will be able to invest in teams.

Who’s in? The N.F.L. has whittled the potential list of permitted private equity investors to just a handful of firms. They include firms that focus on sports, like Arctos Partners and Dynasty Equity, as well as larger firms like Blackstone, CVC Capital Partners and Carlyle Group, which expanded its sports with its recent purchase of the women’s soccer team Seattle Reign F.C. The firms were reported earlier by Sportico.