By Chris Rosvoglou Michael Thomas is back at the Saints’ facility for the start of OTAs, but he’s not ready to participate in practice. On Thursday afternoon, Saints head coach Dennis Allen had an update on Thomas’ rehab process. It turns out the All-Pro wide receiver still needs more time to get his ankle right. “I think he’s doing well in his rehab,” Allen said of Thomas. “He’s not ready yet, but he’s here, he’s rehabbing, getting himself better and we’re certainly anxious to get him out here.” As for when the Saints might have Thomas back at their disposal, Allen hopes he’ll have his No. 1 …