AUBURN HILLS, Mich. — Isaiah Thomas will not sparkle any less or lose any luster if he takes fewer shots in the fourth quarter.

It’s time for the Celtics to readjust after Thomas was smothered by defenses in the fourth quarter of the past two losses at Chicago and Toronto. Second-place Boston is just three games up on the fourth-place Raptors in the Eastern Conference with 24 games left entering Sunday’s contest at Detroit.

This blitzing of Thomas down the stretch is turning into a trend. Thomas is 10-for-30 shooting in the past four fourth quarters of games, including 4 for 16 in the past two losses. Thomas is obviously pressing, trying to live up to that “Mr. Fourth Quarter’’ tag, but defenses are also intent on stopping him.

Toronto’s strategy was pretty simple: allow Thomas to drive into the paint, and then crowd him with bigger defenders to make it nearly impossible to release a clean shot. And when Thomas brings the ball down low, strip him. When he rises for a layup, defend it cleanly. And when he pulls up for a 3-pointer, contest.

“Their point of emphasis was probably to stop me in the fourth quarter,’’ Thomas said after the 107-97 loss to Toronto, in which he was 1-for-6 shooting in the fourth. “And they did a good job of that. They pushed us out offensively, where we were catching the ball beyond the 3-point line, denying us. They played better than us the second half.’’

It’s not that Thomas can no longer be a dominant fourth-quarter player, but the Celtics have to figure out how to be less obvious in showcasing him or make those teams that blitz him pay with other scorers. On Friday, the most aggressive offensive player besides Thomas was guard Marcus Smart, and his aggression always has two sides.

An aggressive Smart can spark the offense, give the team a lift, especially when his 3-point shot is falling. An aggressive Smart can also take poor shots, force the issue, and allow one made shot to turn into five missed ones after that.

The Celtics are banking on Avery Bradley returning soon, perhaps Sunday, and when he does, he immediately becomes the team’s second-best offensive player. After a stellar January (50.3 percent shooting, 46.6 percent from the 3-point line), Jae Crowder has taken a tumble in February (38.1, 27.7), which has placed even more pressure on Thomas to deliver in the fourth quarter.

In that span of subpar fourth quarters over the past four games for Thomas, Al Horford has scored a total of 5 points. One of the drawbacks from Thomas’s marvelous fourth quarters is that his teammates understandably tend to watch more than move. And Thomas has obliged his coaches and teammates by scoring at will in stretches.

Opposing teams have definitely taken notice, fully realizing the best way to beat the Celtics is by not having Thomas beat them alone, but forcing him into more decision-making situations where he may have to put his teammates in scoring positions where they are not comfortable.

The offense was a mess at times Friday, with backup point guard Terry Rozier or Thomas penetrating and passing to unsuspecting teammates or having to attack the rim with defenders waiting. The offense was discombobulated because the Raptors knew most of the Celtics wouldn’t be offensively aggressive.

Coach Brad Stevens stresses for his team to take the open shots, and that confidence has never wavered, but many players have passed up open shots of late, either trying to incorporate Thomas or passing to a teammate at the 3-point line.

When those 3-pointers are falling, the Celtics are a top-five NBA team, when they are not, they are average and beatable. Boston was 5 for 20 from beyond the arc in the second half Friday with just 12 points in the paint. The Celtics need to begin scoring twos to open up the threes and not become so predictable.

Thomas, despite his fourth-quarter dominance, has become predictable and NBA teams are too savvy to allow that to continue. Remember how well the Atlanta Hawks played Thomas during last season’s playoffs?

The difference so far this season is Thomas’s improved decision making and 3-point shot. The 3-pointer is still an essential part of Thomas’s game and opposing defenses are using a Stephen Curry-type arsenal against him, challenging his long-range shots with a considerably bigger player.

Thomas can’t do it all, although he has enough fortitude to try. It’s up to Stevens and his staff in the next few days to devise creative ways to get Thomas easier shots and his teammates shots, period. There is no time to wait.

Gary Washburn can be reached at gwashburn@globe.com. Follow him on Twitter @GwashburnGlobe.