The Steelers are hoping Vance McDonald can do what Ladarius Green couldn't in 2016: Help replace tight end Heath Miller, who left a huge void in a stacked offense when he retired after the 2015 season.

The Steelers on Tuesday sent a 2018 fifth-round pick to San Francisco for McDonald, the 49ers' 2013 second-rounder who signed a five-year, $35 million extension with the team last December. 

"We would like to thank Vance for his contributions to this organization on the field and in the community over the last four seasons," 49ers general manager John Lynch said in a statement released by the team. "Although I have only known Vance for a short time, I quickly learned that he and his wife, Kendi, have been tremendous representatives for the team in the community and their service to others is quite commendable. We wish the McDonald family all the best as they move on to a new opportunity in Pittsburgh."

Playing in one of the NFL's worst offenses last season, McDonald appeared in 11 games and had 24 receptions for 391 yards and four touchdowns. For his career, the former Rice standout has 64 catches for 866 yards and seven scores.

Green battled injuries for most of last season and second-year player Jesse James led all Steelers tight ends with 39 catches for 338 yards and three touchdowns. The group, which also includes Xavier Grimble and David Johnson, struggled with drops during training camp but McDonald -- on paper, anyway -- doesn't magically fix those concerns.

Certainly, some of those issues for McDonald had to do with trying to catch passes from Blaine Gabbert and Colin Kaepernick, and it's reasonable to expect McDonald's production to improve in an offense built around Ben Roethlisberger. Coach Mike Tomlin apparently agrees.

"The guys hadn't been consistently varsity enough for our comfort," Tomlin told reporters Tuesday. "It's as black and white as that. [The tight ends] had some moments positively and had some moments negatively. We were in the market for a guy who was NFL capable. McDonald is that.

"We're not going to anoint him in any way. We're going to put him in uniform like the rest of them and continue to allow them to sort themselves out. It's reasonable to expect the guys that are here to respond positively in the right way to his presence and elevate their play."

McDonald could be the latest piece to an offense that is already among the best in the league. In addition to Roethlisberger, there's Antonio Brown, Le'Veon Bell and Martavis Bryant as well as 2017 second-round pick JuJu Smith-Schuster, who runs like a wide receiver at 6-feet-1 and 215 pounds.