49ers.com's training camp positional previews continue with a look at the wide receivers on the roster. Many of the same faces remain with the club from a season ago, but the San Francisco 49ers have also added four pass-catchers in 2016.Returners:

Dres Anderson, DiAndre Campbell, Bruce Ellington, Quinton Patton, Jerome Simpson, DeAndre Smelter, Torrey Smith, DeAndrew White.Newcomers:

Aaron Burbridge (Draft, 6th Round, Michigan State), Devon Cajuste (Undrafted Free Agent, Stanford), Eric Rogers (Free Agent, Calgary Stampeders), Bryce Treggs (Undrafted Free Agent, Cal).What we know:

With Anquan Boldin unsigned, Smith figured to be the 49ers go-to guy on the outside in 2016. Smith has been outspoken about wanting to improve on his first season with the 49ers where he caught 33 passes for 663 yards and four touchdowns. Smith had a season in Baltimore with 1,000 yards and another with double-digit touchdowns, so he's certainly capable of producing gaudy numbers.

The wideout has already had a positive impression on the new coaching staff. Wide receivers coach Bob Bicknell raved about Smith during mandatory minicamp in June.

"He's a top-level pro. He does everything the way you want it done in terms of preparing and all that," Bicknell said. "I think there's a lot of things we can do with Torrey that's not just as a deep-ball threat. 

"Sometimes when you have that, you want to use that, but there's a lot of other things he can do. I can't wait to watch him play in this offense. We've had some success in the past with that type of guy."

Outside of Smith, playing time on Sundays will be up for grabs.What we'll find out:

So who will claim the other starting spots?

Patton and Ellington are the longest tenured receivers of the bunch and are strong candidates to break out in 2016. Simpson is the veteran of the group with 150 catches for 2,058 receiving yards and nine touchdowns in 62 career games.

Rogers will be an interesting case study as he returns to the NFL following a dominant season in the Canadian Football League. The 6-foot-3 receiver looks the part and made several impressive catches during the offseason program.

That leaves seven pass-catchers who are still largely unknowns, all of whom are either rookies or in their second season: White, Campbell, Burbridge, Smelter, Anderson, Treggs and Cajuste. Those seven will aim to prove that they are capable of contributing on gameday.Quote of the offseason:

"I expect more out of myself. A lot of things you can't control, but everything I could control, I didn't maximize. I want to go out this year expecting to have my best year ever. I always feel that way, and I always work that way." – Torrey Smith on his 2015 season and plans to improve this year.