SEATTLE -- Brandon Morrow’s road to recovery could extend to near the All-Star break.

The right-handed reliever received a Synvisc injection on Monday and will be shut down from throwing for two to three weeks, Cubs president of baseball operations Theo Epstein said Tuesday. Morrow will then need to restart a throwing program, which typically takes six weeks. That could push Morrow’s timeline into early July.

Morrow, who is on the injured list recovering from last season's arthroscopic right elbow surgery, had a setback after a mound session two weeks ago, which spoiled the Cubs’ initial hopes that he’d return in May. He’s in the final season of a two-year, $21 million contract that includes a 2020 club option, and he hasn’t pitched since July 15.

“I think he'll come back,” Epstein said. “I think the Synvisc will help. It was the type of debridement that he had. ... It's not uncommon for it to be a little bit of a bumpy road back. Healing with that type can take a little bit longer, but the Synvisc will help accelerate it a little bit."

Synvisc is used as a lubricant and shock absorber for joints, commonly used to treat knee inflammation. Morrow was shut down last year for a bone bruise.

The 34-year-old signed as a free agent to be the Cubs’ closer after a resurgent 2017 season out of the bullpen with the Dodgers, in which he showed a dramatic velocity increase to 97.7 mph, up from 94.8 mph in ’16. With the Cubs, Morrow pitched to a 1.47 ERA and 31 strikeouts over 30 2/3 innings across 35 outings.

In Morrow’s stead, the Cubs’ bullpen got off to a rocky start, but it has begun to stabilize, with right-hander Pedro Strop filling in as the regular closer.

Montgomery to make another rehab start

Left-hander Mike Montgomery is slated to pitch at least one more rehab start for Triple-A Iowa before he rejoins the Major League club. On regular rest, Montgomery would be slated to pitch Friday for Iowa against Omaha in Nebraska.

On the 10-day injured list with a left lat strain, Montgomery threw 68 pitches over four innings of two-hit, two-run ball against Nashville on Sunday. Manager Joe Maddon said the reports he received were positive.

Montgomery broke camp slated to be the Cubs’ long reliever, though he does have starter capability. In four outings before his injury, Montgomery gave up six runs and eight hits in 2 2/3 innings.