TORONTO -- The Toronto Raptors lost five of their past six games and suddenly the Boston Celtics are snapping at their heels for second place in the Eastern Conference after a four-game winning streak.
The Celtics (23-14) have a chance to move into a tie with the Raptors (24-13) Tuesday night at the Air Canada Centre, when the teams meet for the second time this season.
Toronto won the first meeting, 101-94 at the TD Garden on Dec. 9.
Boston will be without Avery Bradley, who will miss his second consecutive game Tuesday with a mildly strained right Achilles' tendon.
The earliest the shooting guard could return would be Wednesday, when the Celtics are home to the Washington Wizards. He was injured Friday, when he scored 26 points in the win over the Philadelphia 76ers, and did not play Saturday in the 117-108 victory over the New Orleans Pelicans.
Marcus Smart scored a season-best 22 points while starting for Bradley against the Pelicans.
Boston coach Brad Stevens said that Bradley was feeling better after treatment. When the injury occurred, the prognosis for his return was about five to seven days.
"It was Friday, so the fifth day would be Wednesday," Stevens said. "So there's a chance he'd play on Wednesday, but because of the travel, because of the late night, we'll just leave him here and try to get him ready to play Wednesday."
It is not an ideal situation for the Celtics, who must cope with Toronto's outstanding guard tandem of Kyle Lowry and DeMar DeRozan.
"They're really good," Stevens said. "I mean, you want to go in fully healthy, but that's part of it, and that's part of an NBA season. You go in and you play the guys that are available, and our guys are all capable of being really good. And we're going to have to play really good collectively to have a chance to win. That's a good team."
Tyler Zeller, who has a sinus infection, and James Young, is dealing with a sprained ankle, also will not play for Boston.
The Raptors had Patrick Patterson back in the lineup for their 129-122 loss to the Houston Rockets Sunday at the ACC and he scored eight points and grabbed seven rebounds off the bench. He had missed the previous four games with a strained left knee.
Toronto could not hold a 13-point, third-quarter lead against the hot Rockets and also blew a 19-point third-quarter lead Saturday night in Chicago in a 123-118 overtime loss to the Bulls.
The Raptors are enduring a difficult stretch of schedule. They returned from a 3-3 Western road trip to beat the Utah Jazz at home on Thursday, then had to go to Chicago for a game Saturday before playing the Rockets on Sunday.
Toronto committed 19 turnovers leading to 26 points on Sunday, with six of them in the fourth quarter in which the Rockets scored the first 15 points.
"Some of that is shooting ourselves in the foot, some of it is trying to do too much," Raptors coach Dwane Casey said. "We have to take care of the ball. When there is fatigue, we have to regroup. When the schedule is what it is, we have to handle it, stay together, stay focused, stay positive and understand there is a lot of basketball still to play."
The Celtics won 10 of their past 12 games.
The game Tuesday will have a matchup of strong point guards in Boston's Isaiah Thomas and Toronto's Lowry.
Thomas is averaging 28 points per game and scored at least 20 points in 12 straight games. Lowry posted 12 points on 2-for-7 shooting Sunday, but is averaging 22.4 points per game.
Casey said that the Rockets did a good job of double-teaming Lowry "and getting the ball out of his hands."
"Every time he caught it, they had people coming at him," Casey said. "We have seen it before, we have to do a better job of spacing, screening, knocking off the screener before he comes up to set a screen. We have to do a better job of that to get him better looks."