Given the predominantly damp conditions, and with no intermediate tyres available in MotoGP, the circuit was never quite dry enough for slicks, and never quite wet enough for full wets.
For many riders, with just six races remaining in the season, it was a case of too much risk for too little reward, and an opportunity to preserve engines, in particular for Lorenzo and Pedrosa.
Winner of the last two grands prix in Indianapolis and Brno, Pedrosa has closed the gap at the top of the standings to 13 points to Lorenzo.
With no Casey Stoner, the reigning champion still recovering from ankle surgery to repair torn ligaments and remove bone fragments after a crash, the title fight is between the two Spaniards.
However, factory Yamaha rider Lorenzo and factory Honda rival Pedrosa both opted to stay dry on day one of the San Marino event.
In the first session, in particular, just nine riders posted a time, with just one of those a factory rider in Yamaha's Ben Spies.
Italian Danilo Petrucci on his new Ioda-Suter BMW bike led the way with a time of one minute 43.178secs, the conditions meaning that was 10 seconds off of last year's pole lap.
In session two, that ended with light rain after a period when more could arguably have bothered to sit in the saddle, 11 riders managed to stop the clock.
Karel Abraham improved on the best time by just over a second with a lap of 1:42.030secs on his Ducati, 1.174secs ahead of Britain's James Ellison on his ART machine.
Northern Ireland's Jonathan Rea, standing in for Stoner and with an opportunity to prove himself in MotoGP after winning races in World Superbikes, at least managed a few laps on the Honda to finish fifth quickest, nearly three seconds off the pace.
Rea will not be too concerned after recently taking part in the tests at Brno and Aragon to get used to the bike, and as he has also won at Misano in WSB.
Other riders who opted not to bother running were Tech3 Yamaha pair Andrea Dovizioso and Cal Crutchlow, currently fourth and fifth in the standings.
In Brno, Crutchlow became the first British rider to make the MotoGP podium in 12 years, enhancing his confidence as he chases down team-mate Dovizioso whom he trails by 28 points.
The forecast for the weekend threatens rain for qualifying tomorrow, but with the race almost certain to be run in dry, sunny conditions.