The Spaniard crashed into the tyre barriers located at Turn 10 of the Portuguese track in FP2, in an impact that caused several fractures to his jaw and back, as well as severe trauma to the lung area.
Espargaro will remain under observation for another 24 hours in hospital in Faro before doctors assess the possibility of giving him permission to be transferred to Barcelona in the coming days for surgery.
Although it is still too early to calculate the extent of the injuries, it is clear that the Tech3 GASGAS rider will not be able to get back on his bike in the coming rounds in Argentina next week and the Americas GP in mid-April.
In addition to this Sunday's race in Portugal, Tech3 intends not to replace him in the next two rounds of the calendar.
"We won't do it out of respect for Pol," an executive from Tech3 told Autosport on Saturday.
"Then, when we really know how he is and we have a clearer idea of the situation, then we will think of a plan."
The regulations stipulate however that the teams "must make every reasonable effort to propose a qualified replacement within ten days from the time of withdrawal", as stated in article 1.11.3 of the sporting regulations.
Being part of the same group as KTM, it would be easy for Tech3 to use the various testers on the Austrian manufacturer's payroll.
Dani Pedrosa, who will take part in the Spanish Grand Prix at Jerez on 30 April as a wildcard, is joined by Mika Kallio and Jonas Folger, the latter having joined the Mattighofen-based manufacturer's testing structure this winter.
Folger contested just one season in MotoGP in 2017 with Tech3 when it was a Yamaha satellite squad, but couldn't complete the campaign due to a chronic illness.
Ducati will also need to call on a replacement rider for the coming Argentina round next week, after Enea Bastianini suffered a fractured shoulder in a collision with Luca Marini in Saturday's Portugal MotoGP sprint race.
