Field's response is exactly why Arthur had no hesitation in handing him the prized No.7 jumper for Friday's clash with North Queensland.

"We challenged him on a couple of things early in his piece with his training and his response has been excellent," Arthur said on Thursday.

"He had the opportunity to sook about it but he didn't.

"He got on with it and worked on a few things and his response has been excellent to it."

Field comes into the ladder leaders' side after a calf injury to star halfback Mitchell Moses, who is expected to be sidelined for at least two weeks.

The Eels initially feared Moses' injury would be worse.

"It could be two, three, four weeks. So it's not as bad as we first thought," Arthur said.

"He's recovering alright. So we just wait and see."

Parramatta had a number of options to cover Moses' absence, including the possibility of shifting skipper Clint Gutherson into the halves.

The versatile Will Smith and Brad Takairangi were also candidates, while the club signed former Gold Coast prodigy Jordan Rankin last week.

However, Field's maturity made the selection call an easy one for Arthur.

"We wanted to name him straight away in the seven jersey and show that we believe in him," Arthur said.

"We wanted to make our changes as minimal as possible and allow everyone else to do their job.

"He couldn't come into the team at a better time for himself.

"He doesn't have to be Mitch Moses."

Field, who played six of his 11 career NRL games at St George Illawarra last year, was headed to the Super League this year before the deal fell through.

He was then signed on a train-and-trial contract with the Eels, where he showcased his trademark speed and earned a one-year deal.

"He's worked really hard at training, the boys struggle at times defending him because of his pace," Arthur said.

"He's got very good speed and hopefully we get some opportunities where he can show that."

Eels forward David Gower coming in for Daniel Alvaro is the only other change to face a Cowboys side that could get Valentine Holmes back from injury.

STATS THAT MATTER

* North Queensland have won 11 of their past 15 games against Parramatta including four of the past five.

* The Cowboys and Eels are leading the NRL in forced dropouts this season with 16 each.

* The Cowboys will be looking to avoid conceding 36-plus points in three straight away games for the first time since 2008.

Australian Associated Press