Chivas have been a bit of a bogey team for Vancouver in MLS and Rosales played the role of the bogeyman to perfection this year. The Goats have scored four goals against the Caps this season, three of them in that horrorshow performance at BC Place in July. Rosales provided assists on every one of those four goals. He's a Cap killer.
"One of the things I noted about him was when we played Chivas and they had a man sent off," O'Brien told reporters this week when asked about Rosales. "His desire and his work ethic and the edge that he's got to him made him stand out in that game.
"So much so that I checked to see how old he was and was surprised by his age. But that is an important factor and I think they're going to benefit from having him here without a shadow of a doubt."
The best way to remove a danger is to bring it on to your side. It's perfect warfare tactics. Now Vancouver weren't due to play Chivas any more this season (thankfully), but with three Cascadian derbies still left on the Caps' calendar, bringing in a player that knows what is needed to win these matches was a smart move by Robinson.
Rosales certainly knows a thing or two about these games and he'll be thrust into one right away with the critical playoff battle against Portland on Saturday evening and having spent three MLS seasons at Seattle, it's hard to imagine him having any love for the Timbers and he's more than ready to be in the heat of Cascadian battle once again.
"It's one of those games that you always want to be in," Rosales said this week of Cascadia Cup matches. "You always like that passion that the supporters put in. And the trips that the supporters make, to here and Portland and Seattle, has been amazing. Taking supporters in games away. It makes more fun for the players and also the supporters just having the derby teams in their home."
Rosales played in 13 regular season Cascadia Cup matches in his three years in Seattle and the two playoff games between the Sounders and Timbers last season.
With two goals and four assists from those games, both goals and half of those assists coming against Vancouver of course, the Whitecaps will be hoping for more of the same in the remaining two games against the Timbers and his return to Seattle in October. For Rosales himself, he'll relish every minute.
"It is a derby. They're wars," he told reporters this week. "They're everything. It's the game that everybody wants to be there, just to make history. It's a game where we're not just playing the 22 guys on the field, it's playing in the stands. The supporters are also playing in this game.
"If you have a positive result, it's confidence and all this stuff. I always like to be there because the atmosphere is fantastic and this part of the country, facing Portland and Seattle, has been amazing the last couple of years. As a player it's one of the most enjoyable games that we can have."
We maybe shouldn't expect too much of Rosales right away. As they always tell us with investment ads, past performance is no guarantee of future ones. We're hyping him up here big time I know. He isn't the second coming or Lionel Messi, true, but he does have what it takes to be a difference maker for this team in conjunction with others. And he's what the Whitecaps have been lacking of late if he performs to his best.
He is still finding his feet in his new surroundings but all the signs from training this week is that Rosales is settling in with his new teammates pretty quickly and he likes what he sees.
"Obviously you need time to know each other, to know the players, to know the team," Rosales said. "But we have no time, so I'm just trying to do my best with the challenge."
"I'm very happy to be here, to be around the guys that have enough quality to be in a good position and play good soccer. It's enjoyable for the supporters, it's enjoyable for the city too. I see this team growing, growing and growing."