Kelley L Cox-USA TODAY Sports

Kelley L Cox-USA TODAY Sports

The San Francisco 49ers have not been faring well in the positional ranking being released by advanced analytics site Pro Football Focus. The team's quarterbacks ranked 31st out of 32 teams. Their defensive front-seven ranked 23rd, the offensive line ranked 26th, and the group of running backs ranked 18th. The 49ers' wide receivers didn't do any better, coming in second-to-last in the NFL at number 31.

The interesting part is that Pro Football Focus projected both Bruce Ellington and Quinton Patton as starters at wide receiver behind Torrey Smith, along with Vance McDonald at tight end.

Other receivers that they listed under "key depth" included WR Aaron Burbridge, WR Eric Rogers, and TE Garrett Celek. Neither Burbridge nor Rogers have any NFL experience. However, both McDonald and Celek may have prominent roles within Kelly's offense if he continues to use two tight ends as he did last season with the Philadelphia Eagles.

Smith is certainly the leading candidate for the 49ers' number one receiver spot. "49ers QBs recorded an NFL passer rating of 116.9 on throws to Torrey Smith in 2015," said Gordon McGuinness of Pro Football Focus. "Torrey Smith is the best of the bunch, and it will be interesting to see how new head coach Chip Kelly utilizes him coming off the lowest-graded season and worst receiving-yardage total of Smith's five-year career. Dropping 16 of the past 103 catchable passes thrown his way isn't a great sign, but his 6.8 yards after the catch average from a year ago is something that should fit in the new offense."

"At tight end, Vance McDonald and Garrett Celek combined for 512 yards in 2015, but look for that to change if the usage of Brent Celek and Zach Ertz in Kelly's final season in Philadelphia is anything to go by," continued McGuinness in regards to the 49ers' tight ends.

Surprisingly, WR Quinton Patton had the highest 2015 grade from Pro Football Focus at 69.6, ranking him 70th among all wide receivers in the league. That was through 320 passing snaps and 119 running snaps on offense. Smith came in just below him at 73rd with a 68.4 grade, but had a much larger sample size. Of course, WR Anquan Boldin was the highest graded receiver on the 49ers last season with a 79.6 grade. He remains a free agent.

In February, the 49ers signed TE Garrett Celek to a four-year extension on the cusp of him becoming an unrestricted free agent. Last season, he was the team's highest rated tight end with a 71.4 grade, ranking 25th among all NFL tight ends, while McDonald came in with a 65.5 grade.