Tim MacMahon, ESPN Staff WriterOct 1, 2024, 05:27 PM ETCloseJoined ESPNDallas.com in September 2009Covers the Dallas Cowboys and Dallas MavericksAppears regularly on ESPN Dallas 103.3 FMNASHVILLE, Tenn. — Memphis Grizzlies power forward/center Jaren Jackson Jr. exited the first practice of training camp early after feeling tightness in his hamstring on a drive to the basket.”We’re anticipating that it might be a strain,” coach Taylor Jenkins said.Jackson, the 2022-23 Defensive Player of the Year, will undergo imaging on the hamstring to determine the severity.Editor’s Picks1 RelatedThe Grizzlies, who were ravaged by injuries during a 27-55 campaign last season, entered camp with two rotation players sidelined for extended periods.GG Jackson II, a second-team All-Rookie selection last season, had surgery on Aug. 30 to repair a broken fifth metatarsal in his right foot. He will miss at least the first two months of the regular season.Wing Vince Williams Jr., one of Memphis’ best defenders, has a stress reaction in the upper portion of his left tibia. He will be reevaluated around the start of the regular season.