Germany coach Joachim Low has dropped Mesut Ozil and Sami Khedira from the side that desperately needs a victory over Sweden in their World Cup Group F clash in Sochi on Saturday.
Reus got Germany back in the game early in the second half as the Germans launched a massive offensive and when Boateng was sent off for his second yellow card eight minutes from time the Germans continued to push on.
"Now we have to recover and we don't have much time before we have to beat Korea, when we have to play convincingly", said Kroos.
The Germans were at risk of being eliminated after Sweden scored first.
Germany will face South Korea in their final group match on Wednesday and will be keen to win in order to remain in with a chance of topping Group F. Mexico now lead the pack having won their opening two matches, while Costa Rica have already been eliminated.
Germany's matchwinner Toni Kroos has criticised former internationals and pundits for putting the boot into the defending champions after their shaky World Cup start.
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"Toni's shot, what can you say about that?" said Reus. "At this World Cup, a lot of goals have come at the end (of games) and today luck was on our side".
With Germany getting in behind Sweden's full backs at will and fizzing passes across the box, it looked like it might be only a matter of time before they scored, but Toivonen's goal gave Sweden breathing space.
Sweden had been able to contain every attack Germany managed to throw at them, but in the final seconds, Kroos took his chance on a set piece to go around them instead and made the most of it.
"We had already put many crosses in and needed to change our plan", he admitted post-match.
"All I am saying is people behaved in ways you don't, you cheer when you win, you leave the opponents to feel sad, you don't react in the way they did".