49ers' Crabtree tears Achilles tendon

Recommended Video:

The 49ers' future took an unexpected twist Tuesday when wide receiver Michael Crabtree made an innocuous cut during an offseason practice.

As he planted to turn upfield during a noncontact passing drill, Crabtree completely tore his right Achilles tendon, an injury that is expected to sideline him for most of the 2013 season, Jim Harbaugh said.

According to multiple reports, Crabtree, who last year became the 49ers' first 1,000-yard pass-catcher since 2003, is expected to miss six months. If that timetable is accurate, Crabtree will be back in late November, around Week 12.

He underwent surgery at Stanford Hospital on Wednesday morning and his surgeon, Dr. Tim McAdams, gave him a bit of encouraging news following the operation.

"He woke up from the surgery and, first thing, he asked the doc how it went," said Harbaugh, who visited Crabtree and was about 30 minutes late to practice. McAdams "talked about the success of the surgery and that he didn't anticipate that he'd be out for the year, and (Crabtree's) comment to that was that he's got no choice but to be back. Every day now is a healing day, and that starts today."

In the meantime, the 49ers are left to figure out how to fill the sizable void created by the absence of Colin Kaepernick's favorite target. In 2012, Crabtree had career-highs in receptions (85), yards (1,105) and touchdowns (nine), a breakout season that was kick-started when Kaepernick became the starter in November.

In Kaepernick's 10 starts, including the playoffs, Crabtree had five 100-yard games, one more than he managed in his first 51 career contests. Kaepernick had a 123.9 passer rating when targeting Crabtree, throwing eight touchdowns and no interceptions. Kaepernick targeted Crabtree with 94 passes, 55 more than his second-favorite targets, tight end Vernon Davis and wide receiver Randy Moss, a free agent who remains unsigned.

Asked Wednesday why Crabtree became his preferred target, Kaepernick skipped any analysis: "He got open," he explained.

Michael Crabtree became the clear No. 1 choice of Colin Kaepernick in 2012. Michael Crabtree became the clear No. 1 choice of Colin Kaepernick in 2012. Photo: Carlos Avila Gonzalez, The Chronicle Photo: Carlos Avila Gonzalez, The Chronicle Image 1 of / 4 Caption Close 49ers' Crabtree tears Achilles tendon 1 / 4 Back to Gallery

With Crabtree sidelined, Anquan Boldin, 32, is the only established, healthy wide receiver among the 11 on the 90-man roster. The 49ers acquired Boldin from the Ravens in March for a sixth-round pick after the 10-year veteran had 65 catches for 921 yards in 2012.

Beyond Boldin, there is a laundry list of question marks. Mario Manningham and Kyle Williams are recovering from serious knee injuries sustained late in 2012, and only Williams is expected to be ready for the start of training camp. Last year's first-round pick, A.J. Jenkins, is a logical candidate to assume a larger role, but he's coming off a rookie season that featured more drops (one) than receptions (zero).

In the draft, the 49ers selected Louisiana Tech wide receiver Quinton Patton in the fourth round and signed the rookie to a four-year contract Wednesday. Among the rest of San Francisco's wide receivers, Ricardo Lockette, Chad Hall, Joe Hastings and Marlon Moore have NFL experience, but little production. The quartet has combined for 28 career catches.

Harbaugh declined to discuss the possibility of the 49ers re-signing Moss or adding another free-agent wideout such as Brandon Lloyd, who was released by the Patriots in March. Lloyd, 31, took a free-agent visit to Santa Clara in 2012 and remains productive: He had 74 catches for 911 yards and four touchdowns in 2012.

Harbaugh offered his standard response to such speculation: He would only discuss the players on the 49ers' roster.

"We're excited for the young receivers that we have," Harbaugh said. "I really feel that somebody is going to emerge there, because they have to. Competition will create that, and we'll look forward to watching that."

Attendance report: Boldin, left tackle Joe Staley, inside linebacker NaVorro Bowman, cornerback Tarell Brown, center Jonathan Goodwin and safety Darcel McBath did not attend Wednesday's practice.

Harbaugh said Boldin had a prior commitment and McBath was ill, but he did not detail why the others were absent. Each player is presumably healthy, and Harbaugh said they would attend offseason workouts in the future.

"I'm not going to go through every single guy and have you come out here on these days and take attendance and go through what everybody's doing," Harbaugh said. "We know where everybody's at and what their prior commitments were or weren't."

Long snapper signed: The 49ers claimed long snapper Kyle Nelson off waivers from the Chargers and released punter Anthony Santella. Nelson spent the 2012 offseason with San Francisco and was among its final roster cuts.