Chris Coleman is 'hopeful' that attacking reinforcements arrive before next Saturday's clash with Hull City.
James Vaughan's departure for Wigan Athletic on Friday leaves the Black Cats without a senior striker in the squad.
Sunderland have scored just twice in their last seven games and have not hit the back of the net since the 1-1 draw with Birmingham City just before Christmas.
Josh Maja and Joel Asoro have both impressed in patches but struggled against two robust defences in Middlesbrough and Cardiff City.
Coleman admits that they cannot carry the burden for the rest of the season.
He said: "Josh is young and is going to be a good player for us, he’s going to get experience. So is Joel Asoro, we can use them from time to time but we can’t go until the end of the season with these two young players, they need help. We need experience in that department.
"We’ve lost two of our experienced strikers who didn’t want to be with us, they wanted to be somewhere else, nothing we can do. This weekend was always going to be difficult for us, we’ve got Marc Wilson in central midfield when he’s a centre-back. Lee Cattermole coming back when he’s not match fit, but it’s what we’ve got.
"We’re playing catch up. Offensively today we got into the last third and then we lacked a bit of confidence and ideas because we’re young and experienced. This window will be huge for us in that department, we know that, we absolutely know that. It’s not a case of ‘I’m hoping’, we’ve got to do it.
"We’ve got to do it, we need help in that department. We cannot expect and put this pressure on two young boys. They’ve done well, they’ve made big impacts, won us a game, but being realistic we need some support. We’re trying, Martin is working his socks to make something happen. We need something, hopefully this week."
Coleman had earlier in the month said he would not sell Vaughan without a replacement but said that Sunderland's struggles convinced him that something needed to change.
The Black Cats boss said the club are waiting to hear on the availability of their targets
"James wanted to be away, that’s OK," he said.
"It didn’t work out for James with us, I think he scored twice in 23 games, so it never really worked out. We were bottom of the league before some things need to change. We’re waiting but the sooner the better."