The Benetton Treviso lock suffered a left ankle injury during this weekend's 28-5 win in the All Star Game that saw Italy take on the best foreign players in the domestic Super 10 league.
However, the Italian Rugby Federation (FIR) remain optimistic that the 25-year-old second-row will be available for selection.
"The injury is less serious than we had anticipated. Santiago received medical attention immediately after sustaining the injury and we expect him to be available for selection for the game against England," FIR spokesman Giacomo Mazzocchi said.
Italy squad: Forwards - Martin Castrogiovanni (Calvisano), Andrea Lo Cicero (Lazio), Salvatore Perugini (Calvisano), Carlo Festuccia (SK Gran Parma), Fabio Ongaro (Treviso), Cristian Bezzi (Viadana), Marco Bortolami (Padova), Carlo Checcinato (Treviso), Santiago Dellape (Treviso), Andrea De Rossi (Calvisano), Silvio Orlando (Treviso), Sergio Parisse (Treviso), Aaron Persico (Leeds), Scott Palmer (Treviso)
Backs - Paul Griffen (Calvisano), Simon Picone (Treviso), Roland De Marigny (Overmach Parma), Rima Wakarua (Leonessa Brescia), Matteo Barbini (Padova), Manuel Dallan (Treviso), Cristian Stoica (Montpellier), Denis Dallan (Treviso), Nicola Mazzucato (Calvisano), Mirco Bergamasco (Stade Francais), Andrea Masi (Viadana)