A father-son disagreement over team payroll spending reportedly led the Grousbeck family to put their Boston Celtics up for sale, according to The New York Post. Ownership persists that it is selling for "estate and family planning considerations."

The Los Angeles Chargers, owned by the Spanos family, is in advanced talks with two buyout firms to offload a stake. The Miami Dolphins, owned by real estate billionaire Stephen Ross, are also in talks with private equity firms as well as a number of potential individual buyers.

Former Chelsea manager Mauricio Pochettino was hired this week to run the U.S. squad, a move that the national soccer federation said was “supported in significant part” by a gift from Ken Griffin, the billionaire founder of the Miami-based Citadel financial empire.

Sports investing has boomed in the past few years. One of those leading the charge is Ian Charles of Arctos Partners, a firm that raised over $4 billion for its now-closed Arctos Sports Partners Fund II.

Former NFL safety and kick returner Brandon Wilson and former sports broadcast journalist Rashad Johnson have joined the Louisiana-based advisory firm WFA.

Such outside investment can provide NFL team owners with liquidity as some look to cash in on the ever-rising team valuations or fund projects such as building new stadiums.