Who would have thought it would come to this? The Boston Celtics announced Thursday that Kyrie Irving will*undergo knee surgery this weekend and miss the remainder of the regular season and playoffs. That means both key players in the Celtics-Cleveland Cavaliers blockbuster last August are sidelined due to injury, as Isaiah Thomas — now with the Los Angeles Lakers — underwent hip surgery last week. In that sense, Irving and Thomas share a connection of sorts. So, when Irving posted a lengthy Instagram message Thursday afternoon addressing his injury, Thomas fittingly was among the first to reach out to the Celtics star. “Minor setback fam,” Thomas commented in response to Irving’s post, adding