Joachim Loew admits he has several problems to solve after Germany failed to impress in their 2-2 draw with Cameroon as he trimmed his World Cup squad on Monday.
Germany host Armenia in their final warm-up match on Friday night in Mainz before flying out to Brazil the following day and coach Loew says improvements must be made.
Germany open their World Cup campaign against Portugal in Salvador on June 16 and also face the United States and Ghana in Group G.
The German coach has reduced his squad to 23 names from 26 as centre-back Shkodran Mustafi, left-back Marcel Schmelzer and striker Kevin Volland failed to make the cut.
Germany laboured against Cameroon, but Loew was missing his captain Philipp Lahm, goalkeeper Manuel Neuer and midfield general Bastian Schweinsteiger.
"You could see the freshness was missing, our passing game wasn`t good and we made many, many mistakes," said Loew after Sunday`s 2-2 draw against Cameroon.
"It`s something we need to work on, our chance conversion rate is not optimal.
"We also gave away far too much ball and we left too many gaps between midfield and defence in the closing stages."
Loew singled out his chief play-maker Mesut Ozil, who was again off form having been booed off the pitch in Germany`s 1-0 win over Chile in March, on the back of a dip in form and a hamstring injury with the Gunners.
"Mesut Ozil didn`t have one of his better days and he needs two weeks more, but after that we will see a strong Mesut at the World Cup," said Loew.
Cameroon took a shock lead through veteran captain Samuel Eto`o on 62 minutes only for Germany to equalise four minutes later through Thomas Mueller.
German replacement Andre Schuerrle gave the hosts a 71st-minute lead before Cameroon left-wing Eric Choupo-Moting, who plies his trade in the Bundesliga for Mainz 05, popped up with the 78th-minute equaliser.
Loew has a long list of players running out of time to prove their form.
Schweinsteiger is training again after tendinitis of the knee ligament, while Neuer and Lahm are being treated in Munich for shoulder and ankle injuries respectively.
Loew played without a dedicated striker on Sunday, using attacking midfielder Mario Goetze up front as a `False Nine` with veteran forward Miroslav Klose working his way back to fitness.
Borussia Dortmund left-back Erik Durm was impressive on his debut, while Sami Khedira produced a solid display after six months on the sidelines.
Loew`s final squad for Brazil is a balance of youth and experience.
Volland`s axing means veteran striker Miroslav Klose, is the only recognised striker, but, as he did against Cameroon, attacking midfielder is an option as a `False Nine`.
"We have the right balance of young and highly-talented footballers, plus players with lots of experience, who knows what it takes" said Loew.
"Our squad is balanced, there is depth in each position.
"The players and squad have character and we are flying to Brazil with big goals in mind."