Arsenal's Aaron Ramsey likely to miss four weeks - Arsene Wenger

LONDON -- Aaron Ramsey is expected to be out for four weeks with a thigh injury, dealing another big blow to Arsenal's chances of getting back into the Premier League title race.

Ramsey had to limp off just 15 minutes after coming on as a substitute in the 4-0 win at Hull in the FA Cup on Tuesday, and underwent scans on Thursday to determine the severity of the injury.

"I would say four weeks," Wenger said, dismissing speculation that the Wales international could be out for the season. "At the moment, his clinical signs are quite positive."

Centre-back pairing Per Mertesacker and Gabriel Paulista also went off injured against Hull, but Wenger said both defenders should be available for Sunday's FA Cup quarterfinal at home against Watford.

Mertesacker sustained a cut above his after a clash of heads, while Gabriel sustained a hamstring problem.

Wenger said Mertesacker has trained as normal with squad in the last few days, while Gabriel is expected to return to full training on Saturday.

"I don't think he lost too much fitness," Wenger said about Gabriel. "I will have to make a decision tomorrow. At the moment my gut feeling is that he will join in [training] tomorrow and be completely available."

Meanwhile, Laurent Koscielny is also close to returning from a calf problem, but Wenger said he may opt to rest the Frenchman ahead of Wednesday's trip to Barcelona.

"Koscielny is not far," the Arsenal boss said. "Will I risk him or not? It may be a small medical risk, I don't know, I haven't made the decision yet."

While Arsenal's defensive injuries may be easing, Ramsey's absence in central midfield will cause a bigger problem for Wenger, especially as Santi Cazorla and Jack Wilshere are not expected back until April.

Wenger gave Mohamed Elneny his first league start alongside Francis Coquelin against Spurs and said the Egyptian is ready to play a bigger part going forward.

However, he did not rule out switching formations at times to a 4-3-3, as he has done in the FA Cup this season.

"Elneny looks like he's ready to play, yes," Wenger said. "I will consider every formula that is possible to give us balance at the moment. I think Elneny in central midfield can cope.

"We have [Mathieu] Flamini, we have Coquelin who can cope as well -- they have shown that already. We can change the formula as well if needed, but that depends on the game. Every game will be different now."