I was wondering too. Final is a relative term. I think Vukovic was signed after the season started last year. And contracts don't become guaranteed until sometime in the summer, so players are often waived later in the year (Veeder, Francis, Perry, etc).
Given how anemic the attack looked last night, I'm wishing we had signed trialist Sercan Guvenisic. He had a relatively prolific time as a trialist before he got a muscle injury. By all accounts he did well in the SJ reserves last year but couldn't crack into their stellar offense. He brings experience and seems to be willing to work hard. While a totally different style of play, I'm not sure Oduro is the better pickup. This Oduro midfield experiment doesn't strike me as wise, either.