Crystal Palace boss Alan Pardew joked Glenn Murray has a "bionic" knee and hopes the striker can continue to torment Premier League defences.
Murray missed the majority of last season after rupturing a cruciate knee ligament as Palace won promotion to the Premier League via the playoffs in 2013.
The 31-year-old has netted five goals in five games, including in last Monday's defeat of Manchester City, to earn the best goals-per-minute ratio of anyone in the league.
Pardew said: "What he did surprise me with on Monday night is his aerial ability. He really was outstanding.
"I don't know if he's got a bionic knee, but he's got an extra spring from somewhere."
Pardew says the Cumbrian has many qualities -- pace is not among them -- and may have had to adapt his game, like Alan Shearer did, after serious injuries.
"Glenn has had to change his game a little bit and he goes to Sunderland, goals per minute, as the best striker in the Premier League," Pardew added.
"That is great for him, it really is. It is a great tag for him and he can try and keep it for as long as he can."
Pardew believes he is reaping the rewards of Murray being given a chance to find his feet at Reading earlier this season.
Murray scored eight goals in 18 games for the Royals, before committing to Palace on Pardew's arrival in January.
"In defending that decision, of Neil Warnock and the board here, of him going out on loan, he probably did need a few games and it's difficult to get them in the Premier League," Pardew said.
"In a way the loan, which I think was perceived as a negative by our fans, might not have been a bad thing. I'm obviously getting the benefit of that."