"This is to see if his knee responds to rest," said Padres manager Bud Black.
Quentin, who hasn't played since July 30, visited the Kerlan-Jobe Orthopedic Clinic in Los Angeles on Thursday.
"They had the same findings the team doctors did," Black said.
Quentin was hitting .273/.363/.493 in 82 games with 13 home runs and 45 RBIs when he landed on the disabled list on Aug. 10, retroactive to July 31. He ran last weekend in Cincinnati but was sore thereafter.
That's when the team essentially curtails his workout regimen.
Black was asked if Quentin -- who has surgery in October on his right knee and was slowed in Spring Training as he recovered -- could potentially need surgery again.
"It hasn't been discussed in earnest," Black said.
Quentin appeared in 86 games last season and has played in 82 games so far this season. He's signed a three-year, $27 million deal that includes a no-trade clause in July of last season.
The Padres will give rookie Jaff Decker a long look in left field with Quentin out. Decker has started four games in the past week. Jesus Guzman got the start Friday.
The team also figures to take a look at outfielder Reymond Fuentes after the rosters can expand from 25 to 40 players on Sept. 1. Fuentes is hitting a combined .325 this season with Double-A San Antonio and Triple-A Tucson.