Moore initially opted out of the 2020 season in August to prepare for the 2021 NFL draft.
Purdue wide receiver Rondale Moore has opted back in and will play in the 2020 season.
Moore announced his decision on ESPN's College Football Live on Thursday, while coach Jeff Brohm also confirmed it on social media.
On Aug. 6, Moore opted out of the 2020 season, citing the "unprecedented circumstances" surround the COVID-19 pandemic and saying he would prepare for the 2021 NFL draft.
Five days later, the Big Ten announced it would not hold a fall football season but attempt to play in spring 2021. However, the conference reversed its decision last week and said it will hold a shortened season beginning the weekend of Oct. 23-24.
Moore said he feels safe playing this fall after the Big Ten enhanced its safety protocols, particularly its daily antigen testing.
"The Big Ten figured it out, Purdue was doing a great job of keeping us safe, and I felt safe coming back," he said. "For me, it was a no-brainer to come back to school and go prove what I think I'm worth.
"When I decided to leave, I couldn't get a lot of answers to the questions I was asking. Everyone was unsure. I'm a lot more comfortable than I was before I left."
Moore said he will be tested for the coronavirus on Thursday, and if he tests negative, he will join practice with the Boilermakers.
He isn't the only Big Ten football player to opt back in recently after initially sitting out. Last week, Ohio State cornerback Shaun Wade and guard Wyatt Davis returned, while Minnesota wide receiver Rashod Bateman hopes to return to the Golden Gophers. Bateman re-enrolled in school last week and received a waiver to practice with the team. However, the junior must be granted a second waiver to play in games this fall.
Injuries limited Moore to just four games in 2019, but he turned in a sensational season as a freshman in 2018. Moore was a consensus first-team All-American and won the Paul Hornung Award as the nation's most versatile player. In 13 games, he caught 113 passes for 1,258 yards and 12 touchdowns. He also rushed for 212 yards with two scores and had 744 return yards on kickoffs and punts. Moore was the first true freshman consensus All-American in Big Ten history.