Gallup took part in meetings as well as the walkthrough on Wednesday, three days after learning of the death of his brother.
The 22-year-old Gallup was informed of his brother's passing in the locker room by his sister following the Cowboys' 22-19 win against the Atlanta Falcons on Sunday. Dallas improved to 5-5 on the season heading into a tilt with the NFC East-leading Redskins (6-4) on Thursday (4:30 p.m. ET).
Gallup expressed his appreciation toward the organization over social media on Tuesday.
"I want to thank my teammates, the Cowboys family, friends & fans for their love and support. It means so much that y'all are here for me and my family during this time," Gallup wrote on Twitter.
Gallup has recorded 16 receptions for 285 yards and one touchdown in 10 games since being selected by the Cowboys in the third round of the 2018 NFL Draft. He had three catches for 81 yards and a score in Dallas' 20-17 loss to Washington on Oct. 21.
The 6-foot-1, 205-pound Gallup made 176 catches for 2,685 yards and 21 touchdowns in the last two seasons at Colorado State. For his efforts, Gallup earned First-Team All-Mountain West honors.