Arsenal’s summer has not exactly been smooth sailing. As well as a failure to make major additions to his squad, Arsene Wenger has seen a familiar injury crisis emerge before the season has even begun. With several players also not yet up to speed after participating in Euro 2016, it means the Gunners go into its opening game of the Premier League campaign at home to Liverpool on Sunday with a dearth of options.

The problems are most severe in defense. Per Mertesacker suffered a serious knee injury in Arsenal’s opening friendly of preseason against Lens and Wenger confirmed on Thursday that he is unlikely to see action again in 2016.

“Per is at the moment off his feet for three weeks, so of course it is a bit boring for him,” he said. “He is with his family in Hannover, but on the football front he is very frustrated. We think it will be four to five months for both players.”

The loss of the veteran German has been compounded by an ankle injury that has struck down fellow center-back Gabriel. He, too, is set for a lengthy spell on the sidelines.

“Gabriel has an ankle problem, and will be out for six to eight weeks,” Wenger added. “It is a bit better than we feared at the start.”

The one other senior center-back at the Emirates Stadium, Laurent Koscielny, is at least not injured, but he only returned to training this week after being a part of the France team that went to the final of Euro 2016. It would be a major surprise were he to even be in the squad to take on Liverpool.

It means that Arsenal could well go into the opening match of the season with Calum Chambers, who started just one Premier League game at center-back last season, partnered with Rob Holding, a 20-year-old who only recently arrived from Bolton Wanderers.

There is a shortage of options further forward, too. Olivier Giroud and Mesut Ozil are both in the same position as Koscielny of only having just returned to training. Danny Welbeck also remains sidelined with a knee injury and, like Mertesacker, isn’t expected back until the New Year.

It means Wenger has a decision to make on who to start up front. Theo Walcott started four preseason matches as the central striker, but didn’t exactly grab his opportunity to impress and scored just once. Despite just one appearance in preseason after returning from an injury suffered in the final of the Copa America Centenario, Alexis Sanchez could get the start up front against Liverpool.

Meanwhile, there will be disappointment for Jack Wilshere. The midfielder was eager to hit the ground running at the start of the campaign after missing almost the whole of last season, but suffered a knee injury at the end of last month and will now sit out the season opener.

“Jack is doing well, but he will be short for Sunday,” Wenger explained. “He is back in training but will not be completely ready for Sunday.”