At the same time that the Portland Timbers are conducting a head coaching search, they are also actively working to improve their roster ahead of the 2018 season.

Timbers general manager and president of soccer Gavin Wilkinson said Wednesday that the club has identified three key positional needs that it wants to address this offseason.

Wilkinson said that the club hopes to sign an attacking player, a central defender and a defensive midfielder ahead of next season.

While the Timbers scored a Western Conference-leading 60 goals and were one of the most dynamic teams in MLS in the attack when at full health in 2017, Wilkinson said the club wants to bring in yet another versatile attacking player that could add a new dimension to the offense.

"I do believe we have a strong group of players and we have a very strong core," Wilkinson said. "We're looking to add another attacking piece that can give us flexibility in the attacking half, that can play multiple positions and still add a layer for the first team. This would be a proven player that has international experience and somebody that is dynamic, somebody that offers something a little bit different to what we currently got."

Wilkinson also said that the club is aiming to sign a young center back and young defensive midfielder. He said that the club hopes to bring in players at both positions that can make starts and contribute in 2018 while growing and developing with the club for the future.

The Timbers have a handful of key starters at center back and defensive midfield that are at least 30, making it imperative that the club starts to develop a succession plan at both positions. Center back Liam Ridgewell is 33, center back Larrys Mabiala is 30 and defensive midfielder Diego Chara is 31.

"We need to bring in a younger central defender as a succession plan, but somebody also that we can see being a starter in MLS both this year and moving forward," Wilkinson said. "Then we start to look at the age in our midfield... When we start to look at another piece in the midfield that can be a six, potentially an eight, we will start identifying players that are a little bit younger, but have a longer timeline with this club."

The Timbers may have to make some of their key roster moves before they have a new head coach in place due to the opening of transfer windows and the calendar for the MLS offseason.

But the club plans to inform the head coaching candidates on its short list about any potential roster moves.

"Those are three key areas," Wilkinson said. "The discussions will continue with the staff and with the future head coach in identifying other ways for this team to continue to get better."

-- Jamie Goldberg | jgoldberg@oregonian.com

503-853-3761 | @jamiebgoldberg