VANCOUVER - Carl Robinson’s “refreshing” of his Vancouver Whitecaps looks like it will result in the sweeping away of a couple of back line mainstays.

On the eve of Thursday’s MLS Superdraft in Philadelphia, the Caps announced that they have acquired 24-year-old, left-footed Uruguayan centre back Diego Rodriguez, a move that coincides with the apparent departures of Honduran international Johnny Leveron and the popular Andy O’Brien.

Rodriguez, who the Caps have had their eye on for six months and who Robinson personally scouted on his recent trip to South America, comes to the Caps from Club Atletico Juventud de Las Piedras on a one-year loan with a transfer option.

“It’s an excellent signing for us,” Robinson, the Caps’ head coach, said of a player expected to slide in alongside towering Costa Rican Kendall Waston in the centre of the Vancouver defence.

“He’s left-sided, he’s six-foot-two . . . and he’s got a good presence. The fundamentals you want a defender to have he does very well. His footwork is excellent and he’s got good technique in clearing the ball and blocking (shots).”

O’Brien, a 35-year-old English Premier League veteran, started 54 games over three seasons with the Caps, including 25 last season. Leveron, 25, started 33 games in 2013-14.

Robinson said the Caps are still speaking with Leveron, who could be traded, but “we’re not very close to agreeing to anything at the moment (and) I don’t know whether we will come to an agreement.”

O’Brien, who was out of contract, was keen when the 2014 season ended to return for at least one more year, but it was going to have to be at a reduced salary (he made $280,000 in 2014) and perhaps even in a playing/assistant coach role.

Robinson said the club had “very good talks” with O’Brien and his agent, but the veteran, who was a quiet, well-respected leader on and off the field, was now looking at a couple of options in Europe. “We’re going to be moving in a different direction.”

The coach said it was “unfortunate” that the club couldn’t come to an agreement with O’Brien. He declined to say if the sticking point was money or the player’s role.

The Caps have just three centre backs signed -- Waston, Rodriguez and six-foot-three Christian Dean, the Caps’ first-round draft pick in 2014. Dean, recently called up to a U.S. men’s national team training camp, played just 123 minutes in four MLS games in a tough rookie season and Robinson said he’s “itching” to get the big man more first-team minutes.

“I don’t want to create ceilings for young players and block pathways,” he said, which the re-signing of Leveron might do. “It was a learning year for (Dean in 2014) . . . learning how to deal with (negative) situations. His two training stints in Europe in the off-season will make him stronger and more aware of what he needs to do.”

Robinson said that with international call ups, the possibility of injury and suspensions during the 34-game regular-season and the fact Vancouver will also have CONCACAF Champions League and Canadian championship games to play, he’d like to have five central defenders.

He said the club is looking in particular at adding a domestic centre back and suggested there’s a good chance the Caps could draft one with the 13th overall pick Thursday.

Rodriguez spent three seasons in Spain, playing mostly with Malaga’s reserve side. After returning to Uruguay, he started 20 games over two years with Juventud.

Rodriguez said he's grateful for the opportunity in a "world-class city" and expects the club's Latino players to help him adjust to "the team, the culture, the way things are."

“He wants to learn,” said Robinson who spent time watching Rodriguez practice. “He was asking me ‘How can you make me better.’ He’s got the right mentality.”

gkingston@vancouversun.com