Saints' Team Captain was one of ten players to come on for the second half at the Estadi Josep Pla i Arbonés as Jay Rodriguez's double helped them to a 2-1 win against their Spanish third-tier opponents.
And Lallana said that he was pleased that the side managed to start their friendly schedule on a positive note, adding that they could well have scored more goals.
"It's always nice to win games," Adam assessed to Saints Player
. "It's good to get rid of the cobwebs because the first game is always quite tough to get into the swing of things.
"We fielded two different teams more or less, and it was a good workout because they were a strong, physical team.
"We had a few opportunities to score more goals, but the lads are probably a bit rusty at the minute. We won the game but it would have been nice to get a couple more goals.
"We will be reasonably happy with that, and we'll carry on training hard for the next game at the weekend."
It was Lallana's parried shot that set up Rodriguez's second goal
On a personal level, Lallana was happy to play his first game in two months, and also took time to praise two-goal Rodriguez for his contribution.
"It's nice to get back in the swing of things. Your first game almost feels alien, no matter how well and hard you train on the training pitch.
"We were missing Jos [Hooiveld] with a slight injury, so Jay and Prowsey (James Ward-Prowse) had to play an extra 20 minutes or so. Credit to them because your first game is always tough.
"As for Jay, it's always good for goalscorers to keep scoring through pre-season so you can take it onto the season.
"He's a fantastic player and goalscorer, so it was no surprise he got a couple. With him and Rickie [Lambert], whoever is playing up top will chip in with a lot of goals."