No, make that “a certainty” of impending doom.

The Lakers are going to be crushed by the Celtics tonight. May as well just accept it right now and think about dealing with it. All the shots of the annoying Kevin Garnett screaming and pounding his chest, and Boston fans exulting, blah blah blah.

I don’t like the Lakers’ chances in this game. At all. For several reasons.

1. They played last night in Toronto. The Celtics are home and had the day off Wednesday. If you want one sure indicator of trouble in the NBA, this is it: You are a team playing the second of back-to-back road games. The Lakers would be in trouble against the Washington Wizards tonight. Except it’s the Celtics.

2. The Celtics have played very well — 12-0,  to be exact — since they emerged from the 2-7 tailspin the Lakers nudged them into, back on Christmas Day. The Celtics even are getting real contributions from their bench, which seemed to have been exposed as a glaring weakness — for the first few months of the season. That is, losing to the Lakers turned out to be a sort of shock that made the Celtics reevaluate what they were doing, and now they’re back to doing it right, and their sense of confidence (arrogance) is back.

3. No Andrew Bynum. I’m not one of those who believes he is a great player, or ever will be, but he’s 7 feet of protoplasm that clogs the lane. As opposed to Pau Gasol, faux center, who is 7 feet of cellophane. I envision lots and lots of Boston points in the paint.

4. I believe the little rush of adrenaline the team got when it found out Bynum would be gone — as exhibited in New York, especially — should have run its course. The Lakers played over their heads against the Knicks, and spent a lot of energy in the fourth quarter at Toronto last night, and I think they arrived in Boston tired and flat and finally thinking, “You know, we’re better with Bynum,  and this is gonna be hard to overcome.”

5. The Lakers, I am convinced, are not a mentally tough team. Aside from Kobe Bryant. They remember losing in Boston horribly in Game 6 of the Finals last year. They know everyone expects them to lose tonight.  And I believe that, in their hearts and minds, they already have accepted they will lose and, in fact, already are rehearsing all the logical reasons why they will — back-to-back road games, missing Bynum, Boston payback, just being on the road. All that.

However, I expect tonight’s defeat — and I’m thinking it will be in double digits, and maybe even 20 points — is a precursor to being knocked around by LeBron and the Cavs on Sunday. And getting routed twice in four days on national television by the East’s top teams will be an oversized Samsonite of mental baggage they will lug into the playoffs — where they will lose in the Finals to one of those two teams. If they get that far.

This is beyond “I’ve got a bad feeling.” This is one of those, “what can they take out of this that somehow, someway can be construed as positive” situations.

Nothing.

Let’s say Boston 110, Lakers 92.

And let me add this: If the Lakers somehow win tonight — which they won’t, but let’s just throw this out there … If they win tonight, they absolutely, positively can win an NBA championship.

But that is an “if” about the size of the Hancock Tower.