Suzuki has asked to take part in selected MotoGP tests next year, increasing the chances of a full-time return in 2014.
The Japanese manufacturer had been a mainstay of the sport for more than 35 years, but pulled out at the end of 2011 for financial reasons.
Suzuki's MotoGP project leader Satoru Terada revealed plans were underway for a full return back in August, but ruled out making wildcard appearances next season.
Carmelo Ezpeleta, chief of MotoGP rights holder Dorna, revealed Suzuki had instead requested to test next year.
"They are asking us to have some testing during the 2013 season," Ezpeleta told BBC Sport.
"If everything goes well maybe we will see them in 2014."
Suzuki's departure left MotoGP with just three factory teams in Honda, Yamaha and Ducati.
Ezpeleta insisted however that the sport's main priority is to have more competitive races, rather than simply boosting factory numbers.
"Nothing is agreed yet but this [boosting factory team numbers] is not our main issue," he explained.
"We have three manufacturers at the moment in Honda, Yamaha and Ducati. If Suzuki are in we have four, and that would be the same as Formula 1, so it is not a big problem.
"The main thing is to have more competitive races. If we can do that with more manufacturers than all the better, but having competitive bikes is the key."
The series announced in November that a spec ECU and datalogger system will be made compulsory in MotoGP from 2014, on condition of a successful conclusion of negotiations between Dorna and the manufacturers over the supply of prototype chassis and engines.
Ezpeleta said Honda has already agreed to supply prototype bikes for a maximum cost of €1 million.