The duo along with the Bulldogs star signing Kiwi international and Sydney Roosters premiership player Frank-Paul Nuuausala will add another level to the Bulldogs' intimidation factor.

Capped off with Maitland trio Geordie Connelly, Hayden Grainger and Shay Padberg it has been a successful off-season recruiting period for new playing coach Mitch Cullen.

Star half Jarom Haines is the only definite departure, while the Dogs are still hopeful of re-signing Ngangarra Barker and Jayden Young.

Cullen was delighted to be able to secure Metcalf and Penn and said his squad was now pretty much settled for 2020.

"There's a lot of depth and experience in the backs now. It's going to be a bit of a headache to pick a backline first round, but it's a good headache to have," he said.

"I'm pretty sure I've got two quality sides there. From now to kick-off it is about getting it right on the paddock."

Penn, who played at centre in South Newcastle's premiership two years ago, played in the Queensland Cup last year.

Former New Zealand Warriors centre Metcalf had last year off after playing with Central Newcastle for two years after moving from Cessnock.

"I'm pretty happy with the signings I've made in the off-season," Cullen said.

"I've pretty much handpicked everyone that I've signed."

Cullen said competition for spots in first grade would be intense.

"The focus now is on getting our fitness levels right and getting in the right head space," Cullen said.

"Player attitude is going to be crucial going forward as there are going to be some quality players missing starts or even spots in first grade.

"It's going to be an entire squad that wins it and opportunities will come along if you can maintain form.

"There's a lot of experience there, it's just everyone coming together now."

The Bulldogs pre-season matches start with the Hunter Valley 9s on February 29. They have trial matched against Toukley (March 14) and Lakes United (April 4) and the Charity Shield on March 28