SANTA CLARA — Arguably the 49ers' best mystery entering Saturday's final cuts is figuring which wide receivers stay to bolster this season's passing attack.
"Everyone deserves to be here," wideout Anquan Boldin said. "They all do, but unfortunately that's not the way it happens. There are going to be cuts."
Selecting the best backups to Boldin and Michael Crabtree will be general manager Trent Baalke's task as the 49ers' 53-man roster is due by 1 p.m. Saturday.
Veterans Stevie Johnson and Brandon Lloyd are the highest profile backups on the roster cusp. Rookie Bruce Ellington has locked up a spot with his flashy play as a wideout and punt returner. Quinton Patton, a fourth-round draft pick last year, is no lock, nor is 12th-year veteran Kassim Osgood, primarily a special-teams ace.
"Whoever is out there, we'll be comfortable with that," Boldin said after Thurday's exhibition-closing win at Houston.
Lloyd's comeback from a 2013 hiatus has played out in limited fashion. He did not play in three of the four exhibitions, though coach Jim Harbaugh said he looked good in Thursday's warm-ups before Lloyd declared himself unfit to play. Lloyd's injury is unknown but believed to be leg related.
Whereas Lloyd is slated to make the veteran-minimum salary, Johnson's price tag is greater, at $3.7 million. Neither veteran plays special teams, but both are quick, down-field play makers.
Ellington led the 49ers in preseason receptions with 12 for 121 yards, including his first touchdown catch Thursday on a pass from Josh Johnson.
The rest of the 49ers' remaining wideouts had minimal receiving stats, mostly reflecting their scant playing time than the offense's preseason struggles. Boldin totaled three receptions, Johnson and Osgood each had two, and Crabtree and Lloyd had one apiece.
"I honestly could care less about preseason stats," Boldin said. "When we were in the preseason, not at one point did we have all our guys out there.
"Now everything is live."
Center Daniel Kilgore and right guard Joe Looney were the only projected, opening-day starters who played Thursday on offense. Quarterback Colin Kaepernick stayed safely on the sideline, having played seven series in the earlier exhibitions.
Right tackle Anthony Davis didn't play in the preseason while he recovers from offseason biceps surgery, but he's expected to be ready for the Sept. 7 opener at Dallas, otherwise Jonathan Martin might start in his place as he did in every exhibition.
Osgood's plight is unique from the other wideouts. His 6-foot-5, athletic frame offers special-teams prowess that's already kept him in the league 11 seasons. He got cut in a payroll-saving move a year ago before re-signing in Week 2.
"As long as I keep running and do a couple jumping jacks, I'm good to go," Osgood said. "I did a lot this offseason as far as my health goes, by changing my diet and being available to rebound everyday and be available every day. In the NFL, if you are available every day, that speaks volumes for your ability to be on a team."
-- Left tackle Carter Bykowski played every offensive snap Thursday, the first 49er dispatched for a whole game this preseason. He spent last season on the practice squad.
-- Linebacker Nick Moody played 90 percent of the defensive snaps. He's seemingly competing for a backup spot with Shayne Skov, an undrafted rookie from Stanford.
-- Rookie linebacker Chris Borland had an interception return for a touchdown Thursday, but that may not be enough to win a starting spot ahead of Michael Wilhoite. "Mike's had a great camp. I think he has a tremendous shot," Borland said. "Whatever happens, I'll just continue to work."
Borland had a team-high six tackles Thursday, to which he said: "I made some mistakes and made some plays. That's kind of been the story this preseason."
-- Outscored 57-3 in their first two exhibitions, the 49ers won their final two exhibitions by a combined score of 61-20. It was the 10th straight preseason they've won at least two games.
-- Cornerback Chris Cook's interception Thursday gave him a team-high two for the preseason. He had none in four seasons with the Vikings. "I like the (49ers) system a lot and I like the players I'm around," Cook said. "I go against some great receivers every day in practice and they definitely make me better."
-- Right guard Alex Boone. through his agent, declined to comment on his contract holdout, which has exposed him to fines and forefeitures of nearly 1 million.