He also had 0 points in 4 games prior to being injured. So it's not like he was an integral part of the roster even before he got hurt. And that's the thing. He was 24 years old, smack dab in his offensive prime. Today, he'll be 31 years old and he's slowing down from the player he was at 24.
Relatively speaking. He's not good enough defensively to be used in situations where guys like O'Reilly, Couturier, Bergeron, Toews, etc. would make the team as 4th line defensive/PK specialists. He'd only make the team as an offensive player, and he's just not one of Canada's top offensive guys at this point to make a top 6 line.
IF he makes the team, it'll be as the 12th or 13th forward. I highly, highly doubt you'll see him anywhere near line 1 or line 2 (he's not touching line 3 assuming that's the Marchand/Crosby/Bergeron line).
Last time out, the lines were:
Marchand - Crosby - Bergeron
Tavares - Getzlaf - Stamkos
Couture - Toews - Perry
Thornton - O'Reilly - Duchene/Giroux/Seguin
as you can see, your description of offensive/defensive roles wouldn't have fit that team very well - the 4th line, for example, had only one guy there for his defense, with arguably the weakest defensive players on the team alongside him.
I agree a top-6 would most likely include McDavid, MacKinnon, Crosby, Point, Marchand, Marner. All 6 elite producers with dominant two-way games.
A Toews-like checking line could feature three defensive beasts like Couturier-O'Reilly-Stone, for example.
Anything can change this year but those 9 guys I see as automatics at this point. For my last 3 guys I probably lean towards Barzal, Bergeron, and Tavares, as all three are all currently tough usage centers with very good results on both ends of the ice. I have to note though that at age 36 Bergy is declining and needs to prove he's still up there during the season this year.
Personally, like I said, I see the guys who are legitimately defensively weak as Stamkos, Huberdeau, Scheifele - guys who either currently get relatively sheltered winger usage or get exposed defensively in tough center usage. So those would probably be my extra skaters at this point, despite their solid production.
And Toews is a wildcard - if he somehow comes back strong at age 33 after missing a year with long covid, then he puts himself back in the mix too.
All that being said, we've come off of two weird short seasons, and a lot will be determined by how the players play in the first half of the season, i think.