Alex Oxlade-Chamberlain (left) is another young player to join Arsenal this summer. Reuters

Tension is building at Emirates, whether Arsene Wenger cares to admit it or not.

Arsenal fans were expecting some major changes, and so far, all that's been added to the club is Gervinho and Carl Jenkinson. Making matters worse, the London club is picking up where they left off with injuries.

In the final pre-season match before the season opener against Newcastle at St. James' Park, the Gunners faced Benfica without Samir Nasri, Cesc Fabregas, Jack Wilshere, Theo Walcott, Abou Diaby, Laurent Koscielny,and Nicklas Bendtner. In the Benfica match, Robin van Persie had "an ankle problem," Kieran Gibbs had a "muscular thigh problem," and Thomas Vermaelen has a "minor back problem."

If there was ever a time for reinforcements, it would probably be now.

"Yes," Wenger recently stated. "We will [be in the market for new players before the season starts]."

One player finally appears to be on his way. It's a done deal that Southampton forward Alex Oxlade-Chamberlain will be joining the Gunners in a £12 million deal. How much Chamberlain contributes to Arsenal this season is any body's guess. The 17-year-old scored 10 goals and nine assists in 34 appearances for the Saints last season.

If Chamberlain appears to lack seasoning, Arsenal may have found a striker who is even more untested in Costa Rican youngster Joel Campbell. Metro reports that the 19-year-old is expected to be announced as a new Gunner for a fee of roughly £900,000 before Saturday.

The two young forwards almost certainly means that Nicklas Bendtner is out. The most likely destination for the Danish forward would be Stoke, who have shown serious interest.

Centre back remains a pressing need, and Wenger knows it. Arsenal reportedly are stepping up efforts to add either Gary Cahill or Christopher Samba. Phil Jagielka was considered the main target, but Everton rejected Arsenal's £10 million offer in July, and there has been no reports of negotiations in more than a week.

A name that has resurfaced is Werder Bremen captain Per Mertesacker. The Bundesliga club announced that they are willing to listen to offers for their star centre back. Sky Sports listed Mertesacker's value at £6 million. If that is accurate, it has the potential to be the best bargain of the summer.

Strengthening the defense is the main priority now that Chamberlain is set to join the club. Gibbs's thigh injury might sideline him for the Newcastle match, and the Gunners are already thin at left back with the departure of Gael Clichy.

As for detractors and those growing impatient with Wenger, former vice-chairman David Dein recently weighed in on the long-time Gunners' boss.

"People have to remember what he's done and achieved," Dein told BBC Radio. "It's easy in life to get rid of people but then what? Getting someone better is the trick."