Rashid returned 9-0-110-0, the worst bowling figures in World Cup history, against England after home captain Eoin Morgan clobbered him for seven sixes at Old Trafford.
"Every day is different, and every wicket is different. You cannot take things for granted," all-rounder Shankar told reporters at the Hampshire Bowl on Friday.
"Tomorrow might be a completely different scenario where we'll have to target him, or we might have to play off. So it is just about adapting ourselves to different situations as quickly as we can."
Most of the Indian batsmen are comfortable against the turning ball and will hope to dominate the spin-heavy Afghan attack led by leg-spinner Rashid.
Shankar, who shares the Sunrisers Hyderabad dressing room with Rashid in the Indian Premier League, said he had tried to read the wily 20-year-old spinner at nets.
"He's definitely one of the best bowlers right now in limited overs, and he has done well," Shankar said about the poster boy of Afghan cricket, who tops the list of T20 bowlers and is ranked third in the ODI list.
"Having played with him for a couple of years, it's very important for me to pick things from him, like whenever I bat against him in the nets, I try and pick his variations.
"He's a good bowler. Anyone can go for runs any day. It is about how we come back strong. So for me, it is about how I play against him tomorrow. That will be the key."
Shankar was picked to bat at number four but Hardik Pandya's better ball-striking ability earned him a promotion against Pakistan.
Shankar denied feeling under pressure to match Pandya's power-hitting.
"The pressure will always be to deliver whatever the situation demands. So it's not about how powerful," he said.
"I've also played down the order. I've also got runs playing at number six or seven. It's not about taking that extra pressure. It's about taking extra responsibility and delivering it at the right time for the team."
Shankar made a memorable World Cup debut against Pakistan, claiming the first of his two wickets with his maiden delivery and scoring 15 not out.
The best is yet to come, said the Tamil Nadu player.
"The last game gave me some confidence, and especially playing against Pakistan, making my debut against them," he said.
"I always look to get better in all three aspects of the game as I know I can keep getting better. I know I can bowl a lot better than what I am bowling even now, so I'm just working on my bowling."
(Reporting by Amlan Chakraborty in Southampton; editing by Pritha Sarkar)
