Recently injured strikers Filip Holosko and Robert Vittek were included in Slovakia's final 23-man World Cup squad on Tuesday.
Holosko, who broke his leg last year, was not able to train with the team until Monday because of residual pain. Vittek had a knee injury.
Neither of them played in a 1-1 World Cup warmup against Cameroon at Klagenfurt, Austria on Saturday.
"It was a tough decision," coach Vladimir Weiss said.
"Holosko isn't 100 percent fit. Or, he may be fit but we don't know what to expect in a real match. It's the same with Vittek. We'll see in the next few days."
The Slovaks will play a final warmup game against Costa Rica in Bratislava on Saturday before heading for South Africa on Tuesday.
The team will open on June 15 against New Zealand before facing Paraguay and defending champion Italy in Group F.
Slovakia will be without its most experienced player, the 33-year-old midfielder Miroslav Karhan, who was ruled out with up an Achilles' tendon injury.
"Karhan deserved to be in the squad," Weiss said. "He was my first choice."
The good news for Weiss was that his two major stars, captain Marek Hamsik of Napoli and center back Martin Skrtel of Liverpool recovered in time from injuries and were already fit to play against Cameroon.
Hamsik had a muscle injury while Skrtel played on Saturday his first match since breaking his foot in February.
Backup goalkeeper Dusan Kuciak made the squad despite injuring his knee against Cameroon.
Slovakia's best striker in the qualifying campaign with six goals, Stanislav Sestak of Bochum, was in, along with two rising stars of Slovak football: Weiss' son Vladimir, Manchester City's attacking midfielder who was on loan at Bolton this season, and midfielder Miroslav Stoch, who won the Dutch title with FC Twente, where he was on loan from Chelsea.
As a surprise, Weiss named the 23-year-old Sparta Prague midfielder Juraj Kucka, who didn't play in World Cup qualifying but impressed Weiss in the training camp in Austria and the match against Cameroon where he scored Slovakia's lone goal.
"For me, these are the best players in Slovakia and I hope that they'll prove it in South Africa," Weiss said.
Slovakia won its European qualifying group to advance to the World Cup for the first time after upsetting favorites Czech Republic and Poland.
Squad Goalkeepers: Jan Mucha (Legia Warsaw), Dusan Kuciak (Vaslui), Dusan Pernis (Dundee United).
Defenders: Peter Pekarik (Wolfsburg), Martin Petras (Cesena), Martin Skrtel (Liverpool), Jan Durica (Hannover), Radoslav Zabavnik (Mainz), Marek Cech (West Bromwich Albion), Kornel Salata (Slovan Bratislava).
Midfielders: Kamil Kopunek (Spartak Trnava), Jan Kozak (Timisoara), Juraj Kucka (Sparta Prague), Marek Sapara (Ankaragucu), Marek Hamsik (Napoli), Vladimir Weiss (Manchester City), Miroslav Stoch (Chelsea), Zdeno Strba (Xanthi).
Forwards: Erik Jendrisek (Schalke), Robert Vittek (Ankaragucu), Martin Jakubko (Saturn Moscow), Filip Holosko (Besiktas), Stanislav Sestak (Bochum).