Philadelphia Eagles wide receiver Jeremy yet undiagnosed malady.

CSN Philly reported on Thursday afternoon that the third-year wideout came back to St. Louis for further testing, but a team official said the trip was announced earlier in the week and originally scheduled to take advantage of a four-day gap in training camp.

The Eagles open up their 2011 preseason slate with a home date against the Baltimore Ravens on Thursday night.

Maclin has seen limited reps in training camp due to the unknown problem, working out on a field separate from the rest of his teammates as team medical personnel have been unable to figure out what is wrong.

The 23-year-old posted career bests with 70 receptions for 964 yards and 10 touchdowns in 16 games with the Birds last season.

As a hedge against any potential problems, the Eagles signed former Giants wideout Steve Smith to a one-year contract on Wednesday.