He's got the skill, size and talent, but the NA schedule is tough for a lot of Euros during their 1st season. At least half a season in the AHL would do him good.
AHL is a good place to get acclimatized to the North American game, but from a conditioning point of view I actually think the AHL is probably more tiring. The AHL in general is full of a lot of grinders and fighters with splashes of skill here and there, it's actually the more physical and chippy league out of the two IMO. Also the AHL does a lot of 3 games in 3 nights kind of stuff, mostly playing on the weekend it's give a longer stretch for recovery, but that heavy workload over a short time period is a real shock to the system. Yakimov will clearly be getting a lot more ice time in the AHL then the NHL so that should not be forgotten.
Then the 2nd half of conditioning is recovering from the strain you've put your body through and the NHL provides a much better support system looking after you and letting you recuperate. I'm guessing the AHL team doesn't have a personal massage therapist, catered healthy food choices, or even half the fringe benefits that NHL players are provided to provide the body everything it needs to heal up.
If Yakimov is going to hit the conditioning wall in the NHL, he will in all likelyhood hit that same wall in the AHL, it's just no one will really notice cause most people don't pay attention to the AHL that closely.
The best justification to send Yakimov down is he is having trouble keeping up with the speed of the NHL game or they think he has high offensive upside and would be better served honing his offensive game in the AHL where the closing speed is just a little slower to give you that extra 1/2 second to make a play.
I'd still like to see Yakimov play in 2 exhibition games where the rosters are more closely resembling actual NHL rosters, before rushing to judgement on him. Also with him being exempt from waivers and us having 3 players (Lander, Pitlick, & Arcobello) who are waiver eligible, I'm thinking he is going to have to straight-up outplay atleast 2 of the 3 to make the team.