Biggar, a world class 10 who played a key role for the British & Irish Lions in South Africa during the summer, is one of the first names on the teamsheet when fit.
That is nothing against Grayson, it is just that the man who arrived at Saints from Ospreys in the summer of 2018 is one of the best fly-half operators about.
So Grayson made peace with that, while also pushing as much as he could to become a true competitor.
But during recent times, the Saints Academy graduate has found another obstacle in his path.
Because when Biggar wasn’t around at times last season, George Furbank was switched from his regular full-back role to fill in at 10.
Furbank played in some big games at fly-half, fulfilling the prophecy of England boss Eddie Jones, who tipped the player to star in the role.
It left Grayson again battling for a place he would have expected to take in the absence of Biggar.
And he admits it was a frustrating experience at times.
“Frustrating is the word to use to sum up last season,” Grayson said.
“For me, I never really got a string of games together.
“I played the first few games and lacked a bit of form.
“I was playing with a bit of a niggle that I couldn’t really shake for a few months.
“Then obviously George played a bit at fly-half and it was frustrating for me to see him slip into that role of No.2.
“It’s always difficult to see someone playing in a role that you potentially feel you should be doing or have been doing, but George is a brilliant footballer.
“We’ve all see what George can do at 15 and he’s trained a little bit with England at fly-half.
“He’s got the skills and he can definitely play at 10, it’s just another opponent to battle with for that spot.
“It’s brilliant to have that competition in the squad and it’s something I’ll continue to relish.
“I felt I took a little bit of a backward step last season but showed good character towards the end to bounce back and get back into the team.
“I tried to take my opportunity again when it came.”
Grayson is keen to listen to what the coaches want from him as he seeks a regular starting spot.
He added: “When George was playing ahead of me for that period of time the coaches and I had some good conversations - some tough and honest conversations but definitely beneficial.
“It was about what I need to work on, how I can get better and how I can wrestle that shirt back off him when Dan’s away.
“If you can blow the cobwebs out early in pre-season you can hit the ground running in the first game of the season, and pre-season’s been good for me.
“I’ve had some good conversations and hopefully I’ll be in a good position to start the season.”
One of Grayson’s most frustrating moments of last season came during a game against Bristol Bears at Franklin’s Gardens.
The Northampton-born back, who has made 60 appearances for Saints so far, was withdrawn with 20 minutes to go in the March fixture.
Saints were leading 21-14 at the time, and Grayson appeared to be controlling proceedings nicely.
Harry Mallinder came on in his place and soon missed a penalty that he would normally expect to make, leaving the gap at seven points.
And Bristol pounced late on, scoring in the 75th and 77th minute to secure a dramatic success at the Gardens.
The television cameras showed Grayson’s anguish, and he admits it was tough to watch on as the team suffered defeat.
“It was another one of those that were frustrating,” he said.
“It was a frustrating time for me because I’d seen George play and that was my opportunity to come back into the team, put my best foot forward and give it my best shot of showing I was capable at this level.
“I felt like I was doing so and I felt like we managed to wrestle the game back after going 14-0 down.
“We’d got into a lead and I wanted to be there and help us get over the line so it wasn’t a frustration at any one person in particular or Harry coming on, it was just that I still wanted to be on the pitch.
“I was desperate to help the team win, which obviously we didn’t do in the end, and it just showed how much it means to play for this club that I was disappointed coming off.
“For me personally it had been a tricky time because I wasn’t in the team, I’d come back into the team and I was just desperate to do well so that was probably what that element of frustration was for me.”
Whenever Grayson does encounter tough times in rugby, he can at least turn to a man there who has been there and done it.
His father, Paul, is Saints’ all-time top points scorer, a Heineken Cup winner and a World Cup winner.
And Grayson said: “As you’d imagine, he’s always the first person I’d talk to if I was questioning things, doubting my own ability or if I was unsure about something.
“He’s the first one to give it to me and be honest with me if I’m not pulling my weight.
“He’ll ask me if I feel I’ve been good enough, why so and so is ahead of me and ask me what I can do day to day to be better than them.
“He tries to break it down to a process about what I need to do and whether I’m trying too hard.
“We do have these conversations, usually on the golf course when we’re playing nine holes together. It’s not usually sitting around the dinner table and having these chats.
“It can be as brief as a couple of minutes or it can go on for half and hour, but it’s nice to have him there to chew the fat and speak about rugby in general.”
It’s still very much a family affair at Saints as Grayson has been joined in the first-team setup by younger brother Ethan.
At 19, Ethan is four years younger than James, and they play in different positions as Ethan is a centre.
He will spend some time on dual-registration with Championship club Bedford Blues this season.
And Grayson said: “He’s little in age but he’s 6ft 3in and 100kg so he’s not so little in that aspect.
“He’s a skilful player and he’s just going to have to play some rugby because he’s missed nearly two years because of the Covid situation.
“So for him to be able to go to Bedford and get a year of men’s rugby, he can really challenge himself as a player and as a person and it will be brilliant for him.
“It’s just nice to have him around the club, to be honest.”
Another person Grayson is enjoying having around the club is summer signing Juarno Augustus.
The South African No.8 has actually moved in with Grayson on a temporary basis.
And Grayson said: “’Trokkie’ is still with me.
“Originally he was only coming over for a week or so until he found a flat but I must be a good cook because he’s still with me.
“He’s got his pretty strict diet of chicken, rice and a bit of veg so that makes it slightly easier.
“I’ve taken him up to Old Northamptonians, my old rugby club, to watch a game and meet some of my mates.
“We’ve played a bit of golf together and he’s definitely experienced a few parts of Northampton.
“There’s plenty more to go and I’m sure he’ll experience them over the next year or two.
“I’m just looking forward to watching him play because he’s tearing up trees in training so hopefully he can take that into the season.”
Grayson now can’t wait to get going as Gloucester come to Franklin’s Gardens for the Gallagher Premiership season opener on Saturday.
And when asked about his own and the team’s goals for the campaign ahead, he said: “I want to keep developing as a player and a person.
“There’s always been a lot of talk about opportunity when Dan goes away, but I’m not going to talk about that this year.
“I just want to be in a position where I’m ready to go at any stage, I want to get better every day and I just want to keep improving as a player.
“I want to keep putting pressure on whoever’s in that 10 position, whether that be on myself to keep getting better or whoever it might be.
“As a team, the sky’s the limit.
“We’re not that young group any more. We got 10 to 12 23, 24, 25 year-olds who have all got a lot of appearances for Saints.
“We want to realise our potential, kick on and go for that next level.”