Copa América - Tena: Chile to keep attacking
Bielsa has since resigned and been replaced by fellow Argentine Claudio Borghi, regarded a more cautious tactician.
But Tena, whose side face Chile in the Argentine city of San Juan on Monday, said he expected few changes.
"It's practically the same squad, and I'd say the same style of play," he said.
"It's true that Claudio Borghi has made some changes, but Claudio Borghi always employs that attacking style that he had at Colo Colo and then again in Argentina."
"He has a very distinct way of playing and some great players, especially in attack."
Borghi coached Chile's top side Colo Colo to consecutive league titles from 2006-07 before a less successful spell at Boca Juniors.
Tena, who is Mexico's assistant coach but is in charge during the Copa, said his squad had "had a rethink" after their players were rocked by a disciplinary scandal before the Copa.
Eight were sent home after CCTV footage emerged showing women entering their hotel rooms during a training camp in Ecuador, causing eight replacements from the U20 squad to be drafted in at the last minute.
"Clearly they lack experience, but not quality and, above all, the hunger to do well," Tena said.
Dos Santos helped Mexico win the CONCACAF Gold Cup last month, the regional tournament for North and Central America and the Caribbean.
"He had a very good Gold Cup and we all saw the quality he's got," Tena said. "But no one wins alone, and we're not going to ask Giovani to save us or score three goals every game."