Ulster centre Darren Cave said that extending his contract with the Heineken Cup finalists was "the easiest decision that I have ever made in my life".
Cave, who has won three Ireland caps and is rated by many pundits as a potential long-term replacement for Brian O'Driscoll, signed a two-year deal that will see him stay at the club until 2015.
"I honestly think that Ulster are going to win something between now and the summer of 2015 and I would never forgive myself if I wasn't around to be a part of that," said Cave.
Best and Muller made their returns after neck and thumb surgery, respectively, and coach Mark Anscombe had always planned to ease the pair back into action, particularly as his side have only a five-day turnaround before visiting Franklin's Gardens this Friday night.
Northampton hooker Dylan Hartley has warned his side that they will succumb to last year's finalists if they dish up a repeat of their winning effort against Sale.
"The message is if we play like that against Ulster next week, yes we'll have a good first half," said the hooker. "But Ulster will play for 80 minutes and will come back and beat us. We're going to have to be better."
Saracens get boost
for Munster clash
Munster back- row Tommy O'Donnell (ankle) is unlikely to win his fitness battle as the two-time Heineken Cup winners begin preparations for their double date with Saracens.
"We've got Munster back-to-back so everyone will be in next week," said McCall, after Sunday's Premiership win against Gloucester, in which he also rested South Africa hooker Schalk Brits and Scotland captain Kelly Brown after their international exertions.
"We take a long-term view on all these internationals but the England players will be involved in the Munster games," he said. "They will be rested after those games because it's important we look after them."
• World champions New Zealand completed a clean sweep of the IRB major annual awards as fly-half Dan Carter was named player of the year for a second time, while New Zealand won team of the year and Steve Hansen landed coach of the year honours.