That is the opinion of ESPN FC pundit and former Liverpool defender Steve Nicol.
Arsenal currently sit fourth in the Premier League table after the 2-0 win over Manchester United at the Emirates.
The Red Devils sit one spot below in fifth with eight games of the season remaining.
Arsenal’s chances of winning the Europa League hang in the balance ahead of Thursday night’s last-16 second leg against Rennes.
Ligue 1 side Rennes lead 3-1 following the first leg in France seven days ago.
Nicol admits Arsenal would be more rested if they exited the Europa League but he does not think they can rely on that route for Champions League qualification.
“If you’re Arsenal right now you want to win every game you play, whether it’s Premier League or Europa League,” Nicol said.
“Yes, if they go out of the Europa League, they’re going to be rested more than they would. That’s the key.
“But at the end of the day, I’m not so sure Arsenal will get in the top four anyway.
“We’ve just spoken about this game and we’ve said where the problems are in the back.
“At any stage and in any game, I’m not comfortable with their back line. I think they can lose goals and give goals up.
“They’ve still got eight games left in the Premier League, I’m not so sure Arsenal, whether they’re in the Europa League or not, get in the top four.
“So they better put a little bit more effort into the Europa League for me.”
United fan and ESPN presenter Alexis Nunes liked what she heard from Nicol, replying: “I think a lot of Manchester United fans will be happy to hear you say that.”
But despite Nicol saying Arsenal must put extra emphasis into the Europa League, he cannot see them getting through against Rennes.
“I’m going to say Rennes go through,” Nicol continued.
“Yes, plenty of goals, but just a little step too far for Arsenal I think.
“Plenty of goals, too much to come back.”
Alexandre Lacazette is available for Arsenal after having his suspension reduced from three to two matches.