The Oakland Raiders are going through a transition. Among the many changes in Oakland are nine new starters on defense, a new starting quarterback and a new offensive scheme. Only 17 players remain from the 2010 team and as many as five of those players are fighting for their roster spot.

One of the positions with the least turnover was wide receiver, where the Raiders returned four of the six players from last season. One of them is second-year man Rod Streater, who made the roster last season as an undrafted free agent out of Temple University.

Streater had just 49 receptions in two seasons at Temple and got his feet wet with 39 receptions for 584 yards as a rookie, but he’s poised to at least double those numbers if the first few days of training camp are any indication. Streater is emerging as the Raiders’ No. 1 receiver and Matt Flynn’s go-to guy in 2013.

During training camp practices this weekend, Streater was one of the only receivers catching everything in sight as the rest of the unit struggled with drops. This is good news for Streater, who dropped seven balls in 2012 and had a higher percentage of drops than any other receiver on the team, according to Pro Football Focus (subscription required).

“This year, I was so focused on running routes and catching balls that I didn’t really have much time (for martial arts),” Streater said after practice Saturday.

It would appear that Streater’s shifted offseason focus has paid off in a big way as Oakland’s defensive backs also struggled to stick with him in coverage. Streater has learned to sell his routes and set up defenders, which have translated to better separation from the defensive backs.

Streater also ran crisp and precise routes and he has more than enough speed to force defensive backs to give him operating space. When Streater didn’t have operating space, he didn’t show any ill effects from cutting back the martial arts training he credited with his strong training camp in 2012.

Streater said he’s also focusing on getting big in the weight room to be able to take hits from defensive backs over the middle, but a full year in an NFL weight room is also benefiting him in other ways.

It can be hard for players to add muscle during the season because their bodies are broken down from practices and games, but Streater clearly took advantage of his time this offseason. Streater’s upper body is noticeably more chiseled than last year.

Streater’s offseason focus on routes, catching passes and the weight room has translated into the ability to be beat the jam of Oakland’s defensive backs, even with less focus on his martial arts. With the departure of wide receiver Darrius Heyward-Bey, the Raiders needed a receiver to play on the line of scrimmage and still get open, and right now that guy is Streater.

Head coach Dennis Allen was asked if there was a point last season where things clicked for Streater after practice on Sunday but said he saw something in him after watching the tapes of him in college.

“I didn’t have any doubt that he was going to be a pretty decent player for us,” Allen said.

There’s a strong possibility that Streater was the Raiders’ best receiver last season and we just didn’t know it. Pro Football Focus has a number of advanced statistics that attempt to gauge the value of receivers and Streater was at or near the top of all of them for the Raiders.

Streater led the team with 1.55 yards per route run, was the most productive in the slot with a catch rate of 75 percent, was the best on deep passes with a 38.5 percent catch percentage and was second only to the departed Heyward-Bey in quarterback rating when passes were thrown in his direction.

Denarius Moore was more productive when you look at yards, receptions and touchdowns, but that’s only because he received a lot more opportunities than Streater. According to Pro Football Focus (subscription required), Moore was targeted 110 times, that’s 35.5 percent more than Streater and he produced only 23.5 percent more receptions.

Not to mention, Pro Football Focus data indicates that six interceptions were thrown in the direction of Moore. Streater had only two interceptions thrown in his direction, which is nearly half the interception rate. Surely some of the interceptions were not the fault of the receivers, but it was clear when watching games last year that Moore and quarterback Carson Palmer were not always on the same page.

Despite Moore being clearly the go-to guy last year, Allen is leaving the door open for Streater to become that guy in 2013.

Moore thrived when he was used as a deep threat in Hue Jackson’s offense in 2011 but struggled as the go-to guy in a shorter-passing offense in 2012. The deep ball is also not really Flynn’s strength, and it doesn’t sound like Moore has been able to develop his skills in the short and intermediate game to the point where the coaches are comfortable.

Meanwhile, Streater continues to be one of Flynn’s favorite targets during practices, which could be a credit to the extra work they put in together at nearby Laney College during the offseason. At the very least, Steater has worked his way into the conversation as the team’s best receiver, and no one should be surprised if the Raiders make yet another transition and make him the go-to guy.

Unless otherwise noted, quotes were obtained first-hand. Follow @ChrisHansenNFL for additional updates from Oakland’s training camp practices on Saturdays and Sundays.