The Warriors will carry that message into the regular-season opener against the Los Angeles Lakers on Wednesday night.
Golden State led by 11 early in the third quarter before the Blazers scored 22 straight points. The Warriors missed 17 shots in a row and were held scoreless for more than 8 minutes during Portland's run.
Stephen Curry had 17 points and six assists, and Klay Thompson scored 16 points for the Warriors, who blew a double-digit lead for the second straight game. Golden State lost 91-90 at Sacramento on Wednesday night after leading by 17 points in the third quarter.
"That's going to be our Achilles' heel. When we're not making shots, how do we defend? What's our personality going to be?" said new addition Andre Iguodala, who had nine points, four rebounds and two assists.
The Warriors ended the preseason 3-4, including wins against the Lakers in Beijing and Shanghai. Portland won its final five games to finish the preseason 5-2.
"Just as we ignored the predictions last year that we weren't going to make the playoffs," forward David Lee said, "we're not going to let the positive outlook change the way we work."
Jackson said he feels satisfied with the way the preseason ended because the Warriors emerged "relatively healthy." The third-year coach still never really got the chance to experiment with lineups in the exhibitions like he had hoped.
Small forward Harrison Barnes missed the last four games with left foot inflammation. His status for the regular-season opener is murky.
Lee also sat out Thursday after undergoing dental work on his two front teeth, which were loosed by an inadvertent elbow from Jason Thompson in the loss at Sacramento. Lee is not expected to miss any time.
Adding to the concerns, Nemanja Nedovic — drafted 30th overall out of Serbia — landed hard on his left wrist and lower back after Mo Williams fouled him on a layup attempt in the fourth quarter. Officials called a flagrant foul but downgraded it to a common foul after a video review.
The Warriors have less than a week to rest up and regroup — not to mention sort out the rotation. With the addition of Iguodala, the question remains: Who will come off the bench?
All five starters — Curry, Thompson, Barnes, Lee and Andrew Bogut — are back from a team that won 47 games last season before beating the Denver Nuggets in the first round of the playoffs and losing to the eventual Western Conference champion San Antonio Spurs in six games. Either Barnes or Thompson will come off the bench.
Jackson is still trying to find the right combination, especially after wasting leads in consecutive losses, albeit in the preseason.
"It is somewhat of a concern, but not overly concerned," Jackson said. "I think that second unit, probably in a normal game, someone will be in there as a calming effect — not just a scorer, but a guy that could get us good looks. With that being said, leaving a starter in the game to take some of the pressure off would be ideal."