Rhinos take on Wakefield Trinity on Thursday in the traditional Wetherby Whaler Festive Challenge.
Agar and Trinity coach Chris Chester have both announced a stronger than usual 19-man squad for the Boxing Day clash at Emerald Headingley.
Three new signings – scrum-half Luke Gale, hooker Kruise Leeming and second-row Alex Mellor – are named in Rhinos’ starting side.
And Agar said: “It does give a number of our players a terrific opportunity to stick their hand up early and make a wonderful first impression.”
Rhinos’ Betfred Super League campaign begins against visitors Hull on Sunday, February 2, two days after Trinity’s season opener away to Hull KR.
Rhinos have been in training since early November and Agar reckons they are ready for a game, if not yet prepared for a full-on contest.
He stated: “Our boys have had a decent break and we think this week’s game will be good for them.
“They want to play. We know we will find out some areas we’ve got to work on and it will be interesting to see where the combinations are at.
“Are we ready for round one today? No, so we will have to temper some of our analysis and assessments by the fact we’ve still five weeks to go until the season, but it will be a great little gauge to see where we are at.”
Agar added: “We fully expect we will have some work to do post-Christmas, but we are happy with where we are at.
“The boys are in terrific spirits and absolutely looking forward to a game.
“For the guys who are making their debut, getting the opportunity to play at Headingley in front of a big crowd will be a great experience.”
The spotlight will be on former Man of Steel and England pivot Gale who missed the whole of the 2019 season, when he was a Castleford Tigers player, due to an Achilles injury.
“He is keen to play,” Agar said.
“It is exciting. He is buzzing, he has been buzzing in training from the word go and I’m looking forward to seeing him play.”
Agar has confirmed Rhinos will visit Spain for a warm-weather training camp next month.
“We are going on January 4,” he said.
“We will have a few days off, then train back on January 2 before we go away for what will be a really important part of our pre-season prep’.
“Everyone will be on board. As many people as possible will be on the field, it will give us some valuable time away and it’ll be a really intense week.”