Olivier Giroud says the Gunners need be more clinical in front of goal to still be in the Premier League title race.
Arsene Wenger's side couldn't find a goal at the Emirates as they played out a 0-0 draw against Southampton on Tuesday night.
The result saw Arsenal drop to fourth spot, five points behind league leaders Leicester City.
"It’s a long way to go and we just need momentum," Giroud told Arsenal Player. "Hopefully we can start that against Bournemouth and then after we have a big February and March until the international break.
"We’re going to see how it’s going to be but we need to keep our heads up and keep working on what we are doing well.
"Hopefully we are going to have better nights to come, because tonight we were a bit unlucky and a bit sad to draw.
He added: "We had so many chances to score and we didn’t do it. We missed chances here and it could have been maybe 4-1 or 5-2 but their keeper did well and it is hard.
"You have to keep the faith and keep believing that you will maybe score. That is what we tried to do but he [Fraser Forster] had a very good day. He was always in the right position and did very well and it is frustrating.
"Now we are five points from Leicester City so it is going to be a hard time in the few weeks to go and we need to get as many points as we can.
"It’s not over - we need to stay positive and be more efficient in the next games to come."
It's the third-straight league match Arsenal have failed to score a goal.