Keyshawn Johnson says the Celtics are reminding him of the high expectations placed on the Philadelphia 76ers with "The Process" and worries that Boston's championship window is closing if the team continues losing to the Miami Heat in the Eastern Conference finals. #NBA ✔️Subscribe to ESPN+ https://plus.espn.com/ ✔️ Get the ESPN App: http://www.espn.com/espn/apps/espn ✔️Subscribe to ESPN on YouTube: http://es.pn/SUBSCRIBEtoYOUTUBE ✔️ Subscribe to NBA on ESPN on YouTube: http://bit.ly/SUBSCRIBEtoNBAonESPN ✔️ Watch ESPN on YouTube TV: http://es.pn/YouTubeTV ESPN on Social Media: ► Follow on Twitter: http://www.twitter.com/espn ► Like on Facebook: http://www.facebook.com/espn ► Follow on Instagram: http://www.instagram.com/espn Visit ESPN on YouTube to get up-to-the-minute sports news coverage, scores, highlights and commentary for NFL, NHL, MLB, NBA, College Football, NCAA Basketball, soccer and more. More on ESPN.com: https://www.espn.com