The Moto2 race winner will graduate to MotoGP in 2017 as part of Suzuki’s all-new line-up with Andrea Iannone.
Rins tested Suzuki’s GSX-RR for the first time on Tuesday at Valencia, and was 21st fastest, 1.881 seconds off the pace set by now-former Suzuki rider Maverick Vinales.
Less than an hour into Wednesday’s session, Rins crashed at Turn 12, and was stretchered away from the scene.
The 20-year-old remained conscious throughout, and after initial checks at the medical centre was then transported to Hospital 9 de Octubre in Valencia.
Doctors there identified lesions on the T8 and T12 vertebrae in his upper back, and he is set to be relocated to Barcelona on Thursday after further neurosurgical consultation.
Rins will miss next week’s scheduled test at Jerez, and will likely have to rest for a month, but recover in plenty of time for 2017’s first test at Sepang from January 30.
“Alex crashed this morning and suffered a crush in a couple of vertebra and it seems he should rest for at least three weeks or one month,” Suzuki team boss Davide Brivio said.
“He will not be at Jerez next week for the private test so we should wait until Sepang.
“It’s a pity because we have lost a bit of time, but the important thing now is he rests as much as possible.
“Now we wish him the best recovery and we will meet him again in Sepang.”
Iannone also crashed at Turn 12 about 15 minutes after Rins – prompting a red flag to assess track conditions and add extra barriers – but was able to rejoin in the afternoon despite pain in his right elbow and set the fourth-fastest time.
“Both crashes today were quite similar, but in Alex’s case he took the line where it seems there was a lot of rubber and as soon as he touched the brake he crashed,” Brivio said.
“It was even more strange with Iannone’s crash because he was riding so slow.
“This incident complicated our working plan a bit, but later-on he could ride again and we were able to get some good information ahead of the private test in Jerez next week.”