Thomas Vermaelen believes his Belgium team-mate Dries Mertens is one of many players Arsenal will have to watch out for when they play Napoli on Tuesday.

Mertens moved to the Italian side from PSV Eindhoven in the summer having scored 37 goals in 62 games for the Dutch side.

And the Arsenal skipper is expecting a difficult game against Rafael Benitez's in-form side.

When he comes on for the national team he makes a difference for us, and he can certainly be dangerous for Napoli

Thomas Vermaelen

"It should be a really exciting game against Napoli," Vermaelen told the official matchday programme. "We saw what a good team they are at the Emirates Cup, and they have brought that into the new season - staying unbeaten in the league so far and having a great result against Borussia Dortmund.

"One of my Belgium team-mates, Dries Mertens, joined them over the summer and - if he plays - will be among those to watch out for. He had a few good seasons in Holland with Utrecht and PSV Eindhoven, and was one of the league’s best players there.

"When he comes on for the national team he makes a difference for us, and he can certainly be dangerous for Napoli."

Vermaelen played 120 minutes in the Capital One Cup game against West Bromwich Albion last Wednesday and was happy to get some much-needed playing time under his belt after spending three months on the sidelines.

"Two hours of football was a challenge for me after three months out, but I was really happy to come through it and was actually quite surprised at how I well I felt in the couple of days afterwards," he said.

"It wasn’t easy, of course, but I felt good physically. I worked hard during my injury so I am happy with how things have turned out."

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source Isaac Moore 1 Oct 2013