Wells was traded to Memphis in December after wearing out his welcome with Blazers management and fans. He was supposed to return with the Grizzlies in January, but the game was postponed because of a winter storm.
The Trail Blazers went 2-2 during their recent six-day road trip.
Portland had won five straight overall before tiring and losing the final two games of its trip in Houston and Dallas.
“Fatigue did play a part, but the way we played in the first half also contributed,” Portland coach Maurice Cheeks said.
The Blazers, who entered Tuesday three games out of the final playoff berth in the Western Conference, have had three days to rest their tired legs and prepare for the surging Grizzlies.
Memphis has won two straight and 11 of 14 to move into sixth place in the West.
Lorenzen Wright put back his own missed shot with 19.2 seconds remaining to cap a 14-point rally by the Grizzlies in an 81-80 win over San Antonio on Monday.
“I wanted to be aggressive and go after the loose ball and get the rebound,” Wright said. “Then the ball ended up in my hands and I went back up strong.”
Memphis held San Antonio to just one field goal over the final 9:27.
Shane Battier had just two rebounds against the Spurs, but is now just four short of 1,000 for his NBA career. He said the team concept has been embraced by the Grizzlies.
“That’s one of the great things about this team. We don’t really have a superstar,” Battier said. “Pau Gasol is our best player, but every night someone else steps up. We have the ultimate confidence in everybody on this team. It starts with (coach) Hubie (Brown), he instills that confidence in us.”
STANDINGS (through March 1): Grizzlies - 4th place, 7 GB, Midwest Division. Trail Blazers - 3rd place, 14 1/2 GB, Pacific Division.
TEAM LEADERS: Grizzlies - Gasol, 17.5 ppg and 7.7 rpg; Williams, 6.9 apg. Trail Blazers - Randolph, 20.8 ppg and 11.0 rpg; Stoudamire, 6.3 apg.
SEASON SERIES: Tied, 1-1.
LAST MEETING: Dec. 7; Grizzlies, 93-79. At Memphis, Wells had 16 points against his former team as Memphis pushed its winning streak to five.
ROAD/HOME RECORDS: Grizzlies - 13-16 on the road; Trail Blazers - 18-10 at home.