Kierstan Bell watched her halfcourt shot swish through the hoop near the end of the Las Vegas Aces practice Friday at T-Mobile Arena and sprinted toward coach Becky Hammon. Hammon was holding an unspecified amount of money in her hand for the first person to make it, and Bell happily snapped up the cash before she took off on a brief victory lap showing off the prize. If the Aces were feeling the weight of expectations on the eve of the WNBA regular season, they certainly didn’t show it. The Aces begin defense of their WNBA title Saturday when they host the Phoenix Mercury at 12:30 p.m. at T-Mobile Arena in a rematch of last year’s WNBA Finals. The team will receive its championship rings in a pregame ceremony. “In my mind, I’ve already got the ring. This is just me seeing it,” star A’ja Wilson said. “I’m excited just to get back on the court again. I’ve been unemployed for a couple of months. I’ve been watching a lot of basketball, but I haven’t been able to play.…