Franklin Gutierrez has still been experiencing headaches as he works his way back into baseball shape.

The Mariners say the headaches are not related to any post-concussion symptoms, but could be part of an inner ear condition. Gutierrez continues to work out daily as the team hopes to get him started on a rehabilitation assignment with Class AAA Tacoma at some point.

"If everything goes well today, we'll leave him back, let him continue to work in Tacoma and then eventually get him on a rehabilitation assignment," Mariners manager Eric Wedge said.

Wedge said the headaches "are less consistent" than before and that the team is working at getting a handle on them.

Gutierrez hasn't played since being beaned on the side of the head near his ear on June 14 by an errant pickoff throw to first base.

NOTES

• Charlie Furbush threw a bullpen session Wednesday as he attempts to return from the triceps pain that sidelined him on the 15-day disabled list just more than two weeks ago in Kansas City. Furbush is expected to be sent out on a AAA rehab assignment while the Mariners are on their upcoming trip.

• The Mariners' starting pitchers ended July with a monthly club record 2.73 earned-run average, tops in the majors. The next closest team was the St. Louis Cardinals at 2.90 while the Tampa Bay Rays were the next best American League team at 3.56.

Geoff Baker: 206-464-8286 or gbaker@seattletimes.com. On Twitter @gbakermariners. Read his daily blog at seattletimes.com/Mariners.