"Shelvin stepped in, and I think he is a guy who is going to be able to help us," Collins said. "I feel good about him being able to be out on the floor and helping us."
The Sixers signed the 6-foot-3 point guard, drafted by Washington, to be their third guard. On Thursday the 10-day contract of former Roman Catholic High and Villanova star Maalik Wayns expired.
Collins said that Wayns' failure to stick with the struggling Sixers (16-23) was due to the setbacks (groin injury, flu) by point guard Royal Ivey at the start of the season. That forced Wayns into action he wasn't prepared for. In 21 games with the Sixers, Wayns averaged 2.7 points and 1.0 assists. He shot just 26.4 percent from the floor.
"We signed Maalik from Day 1 with the idea of him being the third guard," Collins said. "So it wasn't that Maalik didn't do what he was supposed to do. We put him in a role probably he wasn't quite ready to do."
Released by the Wizards at the start of the season, Mack has spent most of this season with the Main Red Claws of the D-League. In 14 games, Mack averaged 20.5 points, 8.0 assists, 4.9 rebounds, and 1.4 steals while shooting 46.2 percent from the floor, 41.8 from three-point range, and 89.6 from the line.
He may be called on sooner rather than later. Starting shooting guard Jason Richardson on Thursday had fluid drained from his left knee and did not practice. The Sixers host the Toronto Raptors on Friday, and Richardson will be a game-time decision.
"I'm just going to come in, compete, play hard every day, and do what Coach asks me to do," Mack said. "If the opportunity presents itself for me to play, I'll play hard and try to make plays for others."
The Raptors (14-25) avenged an earlier loss to the Sixers when they routed them, 90-72, on Jan. 9. A loser of three in a row, Toronto has gone 10-6 since beginning the season 4-19.
Contact John N. Mitchell at firstname.lastname@example.org. Follow on Twitter @JmitchInquirer.