Mkhitaryan will arrive at Emirates Stadium as a proven performer at the highest level, but having failed to make the expected impact at Old Trafford.
Nicholas wonders whether he is capable of raising his game in north London, and believes Arsene Wenger would've been better advised by investing funds brought in from recent sales to acquire France international Martial.
The former Gunners striker told Sky Sports: “I appreciate he [Mkhitaryan] is efficient and a decent team player. Would I take the deal? Yes, I would. But to be totally honest I'd much rather pay an additional £50m to get Martial.
“I think if Arsenal would say to Martial: ‘You can be the next Thierry Henry’. Arsenal made £30m on selling Alex Oxlade-Chamberlain, £20m on Theo Walcott, so go all-in; forget Malcom or other players who may or may not be good prospects, go all-in and give him what he wants financially.
“In the summer Arsenal were willing to take Raheem Sterling but Martial is a far better player and could become one of the best in the world.
“I would hope Arsene Wenger would be talking to his agent, who will already know he is going to struggle for playing time majorly with Sanchez arriving, and saying, ‘Come here where we'll build the team around him’.”
Such an opportunity has passed Arsenal by, with it now up to Wenger and Co to coax the best out of Mkhitaryan.
Nicholas, though, fears that a man who has already flattered to deceive at United could buckle under the pressure once again.
He added: “If you don't handle the situation at Manchester United then there's a question mark over you for me. I just think the club is so enormous that it swallowed him up.
“He reminds me of Alexander Hleb, or even Andrey Arshavin. They have talent and are superstars in their own country but they can't really handle the pressure.”