Signed from Ipswich Town in June 2011 for £8 million, Wickham scored just one goal in 28 Premier League games during his first two campaigns at the club, before spending several months of last season on loan at Sheffield Wednesday and Leeds United, respectively.
Recalled in March by new manager Gus Poyet, however, the 21-year-old proceeded to score five goals in nine games to help the club stage a dramatic escape from relegation, while building up high expectations for 2014-15.
Entering the final season of his contract, though, Wickham rejected the offer of a new deal on Wearside last month and has already been linked to both Leicester City and Newcastle United before West Ham emerged as potential suitors.
With the Black Cats rejecting a £5 million offer from the Hammers, Summerbee believes the England under-21 international still has to repay the club for the loyalty they showed him and doesn’t see what he thinks he can gain from leaving.
‘It upsets me. He’s been offered another contract and, for me, he’s not been good enough since he’s been there,’ he told Sky Sports News Radio.
‘Only at the end of last season he found the form which everyone’s been looking for and now he won’t sign this new deal with just a season left.
‘He’s massive for Sunderland and, if you can get him firing like he was at the end of 2013-14, obviously with Rodwell and a couple more players coming in, with what they did at the end of last season, they can use that as a benchmark and move on now.
‘The club’s been loyal to him when he couldn’t hit a barn door. He’s been sent out everywhere after he was a big signing, but they stuck by him.
‘All of a sudden he’s come back into the team, where they put their arm around him and got the reaction they wanted. He should be thinking now let’s put pen to paper and move the club forward.
‘He could be the marquee player, the Kevin Phillips or Nial Quinn if you like, and I think he should give a bit back to the club,’ he added.
‘He’s got to because, apart from the end of last season, he was nothing but a disaster. What better are you going to get? Sunderland’s one of the most wonderful places to play football, with a 40,000-odd stadium. If you get it going there it’ll be sold out.
‘It’s a great club. What’s he trying to get? What does he think he can gain from a move? He should be with the club’s that honoured him and helped him when he wasn’t doing well, so he’s got to sign.’