De Bruyne was forced off early in the second half of Monday's 1-0 last-16 win over Portugal with an ankle problem, while Hazard damaged his hamstring later in the same game.
Both players have travelled to Munich for Saturday's showdown with Italy, though neither took part in Belgium's final training session ahead of the match.
Martinez admitted on Monday it was unlikely either De Bruyne or Hazard would be fully recovered in time, and the Spaniard still remains unsure if either player will make the squad.
"As you know they have not been able to train today," he said.
"There is still another 24 hours to go and they are positive they can recover. It is now a race against time to make a decision.
"We won't make a decision until the last minute. At the moment it's impossible to say whether they will get fit."
Asked if he is playing mind games by making Italy guess as to the pair's availability, Martinez said: "We are trying to get them fit. It has nothing to do with games or arrogance.
"We are in tournament mode. If they are not available tomorrow, we hope to have them available later."
Injury-plagued forward Hazard has struggled for fitness over the past couple of seasons and Martinez appeared to suggest the Real Madrid man has less of a chance of being fit.
"For Eden, it's difficult as it's a muscle injury," he said. "For Kevin, it's another type of injury. It's a decision for the medical staff. We will then make a decision when we hear back."
The winner of Saturday's match at the Allianz Arena will face either Switzerland or Spain for a place in the final.
Italy needed extra time to overcome Austria in the last round, with that 2-1 victory extending the Azzurri's unbeaten run to a new national record of 31 matches.
Roberto Mancini's side have conceded more than once in only one of their last 18 games at major tournaments, conceding just 13 times in total across that sequence.
Martinez got the better of Mancini in the 2013 FA Cup final, with Wigan Athletic stunning Manchester City, but the Spaniard is full of praise for what his opposite number has achieved.
"Italy are a great team," he said. "They press with many players and are very dynamic, with many players able to counter-attack.
"If I have to mention one quality in particular it is the synchrony. That is credit to Mancini and that is why they are unbeaten for so long.
"Italy and Belgium are statistically the best teams in the European Championship, and the teams that have won the most games since qualifying.
"It's a pity we're meeting them already, just like we faced Portugal too early."
Against no side has Belgium played more games at major tournaments without winning than Italy (four, level with France and Germany).
The only European nations Italy have faced more often at the same tournaments without losing, meanwhile, are Germany (nine) and Austria (five).
However, the Red Devils have won seven of their last eight matches at the European Championships – the exception being a 3-1 loss to Wales in the 2016 quarter-finals.