Marco Andretti pleased to be working with Herta

Marco Andretti is optimistic that the arrival of Bryan Herta on his pitwall will help him to find the focus he needs to reverse his form after a difficult 2016 campaign.

Herta has moved across to replace Michael Andretti as strategist for Marco's races, with Andretti Autosport director of engineering and race operations Rob Edwards filling the gap left vacant by Herta on Alexander Rossi's No. 98.

The opening session of the Phoenix test was an early opportunity for Andretti and Herta (pictured) to get used to working together, and Andretti said the relationship has gotten off to an encouraging start.

"I just think it's a good change-up," he said. "One thing about my dad and I is, we're both very loud on the radio, and that's just always how we operated. And we're fine operating like that, but sometimes people around us aren't.

"Bryan is very good at keeping me focused on the No. 27; how can we maximize the 27. And then it's very easy to be, 'Penske went this fast,' or, 'We need to focus on what we can do to go faster, because it's not the elements we can't control.' And I think that's a good mindset change for us."

Andretti finished 16th in the points last year, with a best result of eighth at Sonoma.