ST. LOUIS - The St. Louis Cardinals say an MRI exam on right-hander Michael Wacha's injured shoulder showed progress, but not enough for him to resume throwing.

General manager John Mozeliak said Monday that Wacha, the NL championship series MVP last fall, will be evaluated again in two weeks. He said continued treatment along with weight training to strengthen the area around the stress fracture was in the pitcher's best interests.

"It's not there yet," Mozeliak said. "I'm sure he's frustrated and would like to feel a little better."

The 23-year-old Wacha was 4-1 with a 2.64 ERA last post-season. He's been on the 15-day disabled list since June 18 and is 5-5 with a 2.79 ERA for the defending National League champions.

The injury is uncommon for a pitcher, so the Cardinals are "creating our own road map," Mozeliak said. The team has consulted several specialists to help determine the course of treatment.

Mozeliak said Joe Kelly, on the DL since April 17 with a left hamstring strain, could return to the rotation Friday at Milwaukee. Kelly allowed a run in 4 1-3 innings and allowed a run on three hits in his third rehab start.

"The hamstring doesn't even seem to be an issue with him right now," manager Mike Matheny said. "After that, it's what does his stuff look like, and he was pretty happy."

The Cardinals have already counted lefty Jaimie Garcia out for the year with a shoulder injury. Garcia is likely to undergo thoracic outlet surgery to relieve nerve issues in his shoulder soon and has bypassed the team's medical staff in favour of Dr. Robert Thompson of St. Louis.

Despite the injuries, Mozeliak believes the Cardinals have plenty of pitching and won't be desperate at the trade deadline.

Left-hander Tyler Lyons was recalled from Triple-A Memphis to add bullpen depth with fellow lefty Marco Gonzales optioned a day after he started against the Marlins.

Matheny said Lyons could be an option to start Friday but emphasized he wouldn't hesitate to use him right away in relief.

Lyons, 26, was 0-3 with a 6.12 ERA in six appearances, including four starts, earlier this season. He went on the 15-day disabled list with a left shoulder strain on May 13 and has made three starts since being reinstated on June 19.

The 22-year-old Gonzales made his first three career starts after being recalled from Double-A Springfield and was 0-2 with a 7.07 ERA, allowing one run in 4 2-3 innings Sunday while walking five. He was a first-round pick last year and is 5-4 with a 1.89 ERA in 13 starts at Class A Palm Beach and Double-A Springfield, and is at the Triple-A level for the first time.