​Meet Day Day Day Thomas, the player whose fun nickname and three-point shooting have made him a summer league sleeper worth watching for the Boston Celtics, a story that originally appeared on NESN. Make NESN your preferred source by clicking here. Day Day Thomas may not be a lock to crack the Celtics’ roster, but the talented guard from the University of Cincinnati is getting a real opportunity to prove himself, starting Friday night as Boston opens NBA Summer League play in Las Vegas. He possesses a memorable name, an intriguing skill set, and several reasons to believe in what he can contribute.
If nothing else, Thomas will command attention simply because his nickname is Day Day. In case you’re wondering, Day Day Thomas is the same person as DaVeon Thomas—“Day Day” is just the first syllable of his first name spoken twice. Hailing from South Carolina, Thomas began his college career at Kilgore College, a Texas junior college, where he posted 19.0 points, 6.0 rebounds, and 3.1 assists per game in his final season before transferring. He spent three seasons with the Bearcats, appearing in 100 games and averaging 10.7 points, 3.2 assists, 2.7 rebounds, and 1.5 steals per game. His defense and versatility helped shape him into a well-rounded guard.
Among his strengths is his three-point shooting, which has evolved into a primary weapon for him. He began at Cincinnati with a 28.0% clip from beyond the arc, but he climbed to 40.2% in the 2024-25 season on a similar volume. The 2025-26 season brought another large increase in his 3-point attempts, as he went 72-of-189 from long range, good for a 38.1% mark. If he can translate that same level of marksmanship to the NBA, paired with the tenacity he shows on the defensive end, he will have at least a fighting chance to carve out a role as a perimeter specialist.
Thomas’ combination of defensive tenacity and shooting versatility could give him a legitimate path to an NBA role, provided his shooting translates under the brighter lights and higher competition of the league. The Celtics are a team that often values players who can defend multiple positions and knock down shots when asked, and Thomas’ skill set aligns with that philosophy. His performance in the Summer League will be closely watched, as it could determine whether he earns more time with Boston or remains on the fringes of the roster.
For Celtics fans eager to learn more about the franchise’s ongoing storylines, the team’s latest developments are always worth following. The Garden will host a new chapter as Boston evaluates its depth and potential contributors through the Summer League process, a crucial step in shaping the roster for the upcoming season. Whether Day Day Thomas becomes a permanent fixture in Boston’s rotation remains to be seen, but his path to an NBA opportunity has clearly begun with a strong Summer League showing.
As the preseason unfolds, fans will also want to explore the broader history of Celtics success and the franchise’s enduring culture of competition. Understanding the team’s championship lineage provides valuable context for how players like Thomas are evaluated and where efforts to improve the roster fit into the long-term goals for the organization. Staying informed through reliable sources remains essential for anyone following the Celtics’ pursuit of continued success in the NBA.