The 21-year-old striker paid off another sizeable portion of his £8.1million transfer fee on Sunday when he scored twice in a 4-0 demolition of 10-man Cardiff which lifted the Black Cats out of the Barclays Premier League relegation zone.
That took Wickham's tally to five league goals in six starts - all of them in the last three games - since his return from a loan spell at Sky Bet Championship Leeds, a return which has seen him belatedly catapult himself into the affections of fans who had all but given up hope of top-flight survival.
However, far from flashing an "I told you so" message to his detractors, the England Under-21 international is concentrating solely on completing the job his heroics have made possible.
Wickham said: "I have said all the time, I just want to play football and if I play football...
"I played numerous games at (Sheffield) Wednesday and Leeds - I didn't manage to score at Leeds, but at Wednesday, I was in the same form and it's been recognised for me just to come back in time, score some goals and just to show the manager I have got what it takes.
"But I am not going to dwell on the past, I am not going to hold any grudges. I am here now, I am scoring goals and we are moving up the table, so me and the rest of the team are really happy."
Wickham arrived on Wearside from Ipswich as a precocious 18-year-old in June 2011 as then manager Steve Bruce invested heavily in his potential.
However, his first 37 Premier League appearances included just 12 starts and one goal and were punctuated by a series of loan spells.
His future at Sunderland looked to be bleak when, having failed to make a real impression under Bruce, Martin O'Neill or Paolo Di Canio, he was sent to Wednesday in November and later Leeds by Poyet.
However, a run of eight goals in 11 appearances for the Hillsborough club persuaded the Uruguayan to give him another chance with Steven Fletcher injured and Jozy Altidore and Ignacio Scocco becalmed, and he has never looked back since.
Wickham said: "I came back and the manager said 'Just go and do what you do' and at the end of the day, I am just doing what I get paid to do. I am playing football and thankfully, I am scoring goals."
Wickham trebled his Premier League goal haul with a double in a surprise 2-2 draw at Manchester City on April 16, and struck again as the Black Cats condemned Chelsea to a shock 2-1 defeat at Stamford Bridge last Saturday.
He was at it again on Sunday, opening the scoring with a deft 26th-minute header and then after Fabio Borini's penalty and a third from substitute Emanuele Giaccherini, completing a crucial victory by repeating the dose at the death.
The win gives the Black Cats genuine hope of avoiding the drop - two victories from their remaining three games will almost certainly keep them up whatever happens elsewhere.
But as he and his team-mates prepare to take on the challenge of securing a first league victory at Manchester United since May 1968 on Saturday, it is collective, rather than individual, achievement which dominates Wickham's thoughts.
He said: "It's not about me personally, it's about the team. We are going to go into every game positive that we can win.
"We have gone to City and we have taken a point; we have gone to Chelsea and we have taken three points. We are on a high, so we just need to remain calm and do our thing."
By contrast, Cardiff will return to the north-east next weekend knowing defeat at Newcastle could prove fatal.
Manager Ole Gunnar Solskjaer was deep in conversation with former United team-mate Wes Brown following the final whistle at the Stadium of Light, and he is banking on another reunion next season.
He said: "We are good mates and we both can still do it, those were the words between us.
"The two clubs know we are capable of it. They are capable of it, so let's see who does it at the end."