Boughner said Luongo, 38, whose 459 wins and 74 shutouts rank first among active goalies, would not be rushed back until he's fully healthy.
"He is on the road with us right now," Boughner said. "He is rehabbing. There are good days and bad days. He went through a stretch there where he was really progressing well. In the last week he had a little bit of soreness so we are sort of backing off. We want him to come back 100 percent, not 90 percent, so we are going to be very careful with him."
Backup James Reimer has started the past 14 games for Florida, going 7-5-2 with a .930 save percentage and two shutouts. Reimer is 11-11-5 with a 3.01 GAA and .912 save percentage in 28 games this season.
The Panthers, who have lost three straight games (0-2-1), play the St. Louis Blues at Scottrade Center on Tuesday (8 p.m. ET; FS-MW, FS-F, NHL.TV). They play the Calgary Flames at BB&T Center on Friday before having six days off.
Florida is fifth in the Atlantic Division with 40 points, 12 points behind the third-place Toronto Maple Leafs and seven points behind the Pittsburgh Penguins for the second wild card from the Eastern Conference into the Stanley Cup Playoffs.