The Patriots’ collection of tight ends is among the best in the league. When the group is healthy, there is no debate. That’s why it’s hard imagining them adding any more players to that stable from this year’s draft, especially with only five picks at their disposal. But with Bill Belichick, all bets are off. What we do know, what seemed fairly evident prior to Aaron Hernandez and Rob Gronkowski both going down last season at various times with injury, is the Patriots were very much a tight end-centric offense. It was built around Gronk and Hernandez. The offense flowed through them. Looking ahead, there’s no reason to believe that thinking will change. With the personnel on hand, with or without Wes Welker, this still has the makings of an offense that could regularly utilize two- and three-tight end sets. Gronkowski and Hernandez, who both received hefty contract extensions last season, will be returning. Daniel Fells is still on the roster. Michael Hoomanawanui is a restricted free agent. Then, there’s the wild card: Jake Ballard. He’s a bit of a mystery man, and a possible ace up the sleeve, since he spent all of last season on injured reserve. He could be the guy who ultimately helps shape the offense going forward. It’s not hard to recall the Giants weren’t particularly thrilled when the Pats claimed him off waivers. But that’s the gamble the New Yorkers took — thinking they could slide him through because he had a torn ACL, one suffered in Super Bowl XLVI against the Patriots. Remembering how much damage Ballard inflicted on them in 2011 and how good he looked in the Giants offense, the Pats opted to claim him even though he was hurt and likely out for the season, and despite being well-stocked at the position. With the injuries to Hernandez and Gronkowski last season, they could have used Ballard, but he needed to rehab the knee, and by all accounts, should be ready to go in 2013.