By Arsenal correspondent Tony Hughes

Laurent Koscielny has defended Alexis Sanchez after Rio Ferdinand claimed the Arsenal star has not reached the heights of his outstanding debut campaign.

The Manchester United legend hailed the Chilean as a “fantastic player” on Tuesday but does not believe he has had the same impact in his second season in England.

Sanchez took his goal tally for the season to nine on when he scored twice and set up Mesut Ozil’s opening goal as Arsenal defeated Dynamo Zagreb 2-0 to keep their Champions League hopes alive.

Koscielny told the Arsenal website afterwards why the attacker is such a tough opponent.

“Alexis is interesting when he plays with the ball,” the Frenchman said. “With the runs [he makes] he’s very important because he’s so quick. For the defence, it’s very hard to defend against him.”

However, former England defender Ferdinand has been underwhelmed by Sanchez following his sensational debut campaign in which he scored 25 goals and made the six-man shortlist for the PFA Player of the Year award.

“For me, last season he was defining games with goals and performances,” Ferdinand told BT Sport Europe on Tuesday night. “He was scoring goals at vital times and was the man they looked to when things were not going right and they needed moments of inspiration.

“There hasn’t been many times this season when he has done that. He hasn’t changed games. When they have needed moments of brilliance there hasn’t been that type of moment that galvanises a team and a squad.”

Arsene Wenger has said he will give the wide forward a mid-season break to give him a much-needed rest following an exhausting programme over the last 18 months.

But Sanchez was in the starting line-up for the 17th time in Arsenal’s 18 Premier League and Champions League matches this season as the Londoners defeated Dynamo.

Red alert: Alexis Sanchez is exhausted after heavy programme

“After 10 or 15 minutes, we played with more confidence and we scored,” Koscielny added. “After, it was easier to play. I think tonight all the team did a great job.

“For us it was most important to win, keep a clean sheet and have the cards in our hands for the last game at Olympiacos.

The victory means Arsenal go into their final Group F match with a chance of qualifying for the competition’s knockout stages, providing they beat Olympiacos by two goals or a score of 3-2 or higher in Greece.

Ferdinand believes that the Sanchez remains the team’s principal matchwinner and Arsenal’s best hope of remaining in Europe’s leading competition.

“He is a fantastic player and the talisman,” said the former England defender. “You take him out of the team and who else is there left in terms of someone who can inspire the others. “He [Wenger] doesn’t have that player who can take on that responsibility.”