"My brother told me Mark was playing very well in Spain and everyone was really excited about him," said Alonso.
"I spoke to him a lot before the end of the season because I was really concerned about the team's position in the table, but they did well to reach a safe position and were very happy with Mark.
"Mark made it clear how much he was looking forward to coming to play for Liverpool, but he really enjoyed his time with Real Sociedad and was happy for the chance to play every week, especially after being injured for six months.
"It was good news for him, Real Sociedad and Liverpool that he played so well there."