The 28-year-old defender made a solitary appearance for the Three Lions in 2012, but since then he hasn't figured in Three Lions manager Roy Hodgson's plans.
In an interview with the Daily Mail, Krkic praised Shawcross, saying: "He's really tough. Thank God, Ryan respects me and lays off me a bit in training!
"He doesn't go after me and attack me like he attacks the opposition in games. He works so hard, in the gym and in the training sessions. He sets the standards for everyone.
"He had a really difficult time with an injury but it is as if he's never been away. He is a strong character, a person that every dressing room needs.
"For me, Ryan is an excellent centre-back and he has huge experience now in the Premier League.
"He is a super professional and a true leader. I think he could very easily play in the English national team."