Sunderland manager Sam Allardyce believes the determination of midfielder Lee Cattermole will be key in their bid to avoid Premier League relegation.
Cattermole was dropped last month in favour of Jack Rodwell but has since returned to the starting XI for the last four games, from which Sunderland have taken five points.
Allardyce's men are outside of the relegation courtesy of their goal difference being superior to that of Norwich City, with arch rivals Newcastle United - who have played a game more - one point behind in 19th.
The Wearsiders have four games with which to secure their place in the Premier League for next season and Allardyce expects the combative Cattermole to play a crucial role.
"Having that driving force in midfield is very important in the engine room," Allardyce said.
"Jack's technical ability in many ways is as good as anybody we've got. But Lee's grit, desire, drive and determination can lead the team and make them feel good.
"We can rely on him to break up the opposition's attacks, close their danger men down and use it well.
"Alongside [Jan] Kirchhoff, who intercepts more balls than anyone we've ever had, that's a key factor why defending has become a bit easier for us."
Sunderland have kept clean sheets in three of the last four games, and Allardyce says they must maintain that solidity at the back in order to stay up.
"You've got to have some quality to create and assist, but you've also got to have one that's resilient when not in possession to stop the opposition scoring," he added.
"The fewer mistakes we can make now, the better chance we've got of winning.
"It will be the opposition capitalising on our mistakes, rather than them creating wonderful goals, which hurts us."