The Toronto Raptors will be without point guard Kyle Lowry and forward Landry Fields because of injury for Saturday night's home game against the Philadelphia 76ers.

Lowry left Tuesday's loss to Oklahoma City with a sprained right ankle and also missed Wednesday's game in Dallas.

Fields has been experiencing tenderness in his right wrist and saw a specialist this week. He's scheduled to get a second opinion next week.

Toronto (1-4) has dropped two straight, while Philadelphia (3-2) has won two in a row, including a 106-100 win over Boston on Friday night.

Good numbers thus far

The off-season acquisition went into Tuesday's game averaging more than 23 points and seven assists a game. Just before halftime in Oklahoma City, he fell to the floor in pain after stepping on the foot of the Thunder's Serge Ibaka. The two had got tangled up under the Raptors net.

Lowry has been a big bright spot on Toronto's young NBA season, running the team with hustle and intensity. He's also sixth in the league in efficiency rating — behind LeBron James, Anderson Varejao, Marc Gasol, James Harden, and Rajon Rondo — and is the only Raptor in the top 50.

"Kyle was playing really good, he runs the court. . . looking forward to having Kyle back," said veteran centre Andrea Bargnani.

Regardless of whether the Raptors have Lowry back in the lineup on Saturday at the Air Canada Centre, Bargnani said there are couple of glaring deficiencies the team needs to fix now.

The Raptors have dug themselves first-quarter holes in every game this season. They've also dropped off defensively a season after turning their woeful defence into something respectable.

"As a team we cannot afford to have such bad starts, that's from the first game of the season," Bargnani said.

The Raptors trailed by 11 points at halftime Wednesday at Dallas but outscored the Mavericks — too little too late — by six in the second half.

'This league is about competing and when teams see you not competing, they try to attack.'—Raptors head coach Dwane Casey

"I think the main thing was guys decided to come out and compete, that was the difference between the first half and the second half," Casey said. "That was the difference between the first quarter and rest of the game at OKC. Our starts have been horrendous.

"It's about competing, this league is about competing and when teams see you not competing, they try to attack. That's what they did. We turned the table in the second half, but we can't wait and then dig ourselves such a hole and then try to dig ourselves out of that hole after we've built an eight-point deficit or 10-point deficit."

The Raptors have also plummeted in defensive stats from last season, when Casey implemented a defence-first philosophy in his first campaign in Toronto.

"We're not playing very good defence, it's pretty bad, so we've got to get better, to what we were doing last year," Bargnani said. "All our numbers are worse than last year defensively, so we've got to get back to that.

"That's on us, that's on every player on the floor... we've got to pick it up."

Casey argued that it was on him.

"That is our major problem, we've got to hang our hat on our defence. Sometimes we get caught up in: we've got to play fast, we've got to play up-tempo. And we lose our identity. We've lost our identity, it was happening in exhibition, we got away from our core which is our defensive base," said the coach.

"We've got to get back to that, we've got to get those numbers down."

Casey said the team's major defensive weaknesses are not controlling the paint and not getting back in transition.