Slack defending and a lacklustre second-half performance resulted in an understrength Poland side losing their second match in three games. After the match Janas said he might have to rethink his options before naming his final 23-man squad on May 15.
"I had in my notebook a group of players but a number are simply out of form," he told a news conference. "In the form we saw today, we have no chance of getting out of the group at the finals."
In March the Poles won 2-1 against fellow finalists Saudi Arabia but were unlucky losers 1-0 to the United States in a snowbound game in Kaiserslautern.
Deprived of much of his first choice squad on Tuesday, Janas' makeshift back four were caught napping by a quick throw-in after 14 minutes, flicked on for midfielder Andrius Gedgaudas to volley home unchallenged from eight metres.
The Poles dominated for the rest of the first half and went close with drives from Trabzonspor midfielder Miroslaw Szymkowiak and Sebastian Mila.
Liverpool's reserve keeper also saved the Poles with a pair of timely interventions on the edge of the box as Lithuania's forwards sprung the offside trap with ease in the first half.
Three changes at halftime gave the Poles firmer control without creating many clear cut openings for a front pairing of Southampton's Gregorz Rasiak and Wolves' Tomasz Frankowski.
"This confirmed my worst fears," Janas told public television in an on-pitch interview after the game. "We can see that the majority are out of form and after this game I'm just left with headaches."