The Greece international spent last season on loan in Serie A, making just six league starts and five in the Europa League, exclusively at wing-back rather than his customary left-back role.
Now 30 and in the final year of his Liverpool contract, Tsimikas is back on Merseyside to compete with Milos Kerkez for the left-back spot. He travelled with the squad on their pre-season tour of the United States and could feature against Sunderland in Nashville this weekend.
Tsimikas reported for pre-season training early, giving him a head start on adapting to Iraola's methods, and has already noticed a shift in emphasis on the training pitch.
"We did some throw-ins, some build-ups and all these kinds of things; he likes the intensity in the training, everything is with the ball," Tsimikas said. "He wants us to keep the ball, don't lose the ball, and try to play good football.
"As I say, it's very early, it is new for us, but all the players try to give absolutely everything to try to understand what exactly he wants and to do the right things inside the pitch."
Reflecting on his season away with AS Roma, the defender described it as a strange campaign but insisted his connection to the club never wavered.
"I couldn't wait, to be honest. I had a very tough and strange season last year, but I'm fully here, I trained so hard alone in the off-season.
"And during the last season, even if I didn't have so much game time for some reasons, I'm really here, I'm really happy to be back, really glad and I can't wait to wear the jersey.
"For me, it's like I never left the club. It has a very big sense in my heart always. I'm very happy even now I came back, I just feel like I never left.
"The mood is in the best levels, even the young kids are very positive and try to give everything. All together, we try to achieve our goals."
Speaking to liverpoolfc.com, Tsimikas also stressed the importance of pre-season in laying the groundwork for the campaign ahead, and praised the impact of the squad's younger players.
"The pre-season is the foundation of the whole year. All the players want and try to give absolutely everything to be ready for the first games of the league.
"I think we improve in some parts, even with the young kids that came - the older players, we try to help them. It's a start with the new manager. I really enjoy it, I really try to work very hard and to be healthy. And always I want to improve."