The former Peterborough United stopper wrestled back control of the number one spot from Mark Howard last month but is taking nothing for granted.
Phil Parkinson warned both of his keepers that he would not be treating either as an automatic first choice when they agreed moves to the Macron in the summer.
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Howard struggled on his return from injury in February against Sheffield United and Bristol Rovers, leaving Alnwick to start the last five games, four of which have been victories.
And the 30-year-old feels the competition to get the nod from the manager each Saturday has been beneficial for his game.
“My aim is always to play and keep my shirt,” he told The Bolton News. “Right now I have got it but I know that can change. It keeps me on my toes.
“Having someone like Mark breathing down your neck pushes me on. He is a top keeper and when he came back it isn’t always easy to step straight back in.
“It is a daily battle. We’re trying to push each other and it can only be good for us.”
Alnwick did make an error in the build-up to Oxford United’s first goal at the Kassam Stadium on Tuesday night and knows it will be analysed at the training ground this week with goalkeeping coach Lee Butler.
“We’ll talk about things. I’ll go in on a Monday morning and say ‘I’m not sure if I should have done this, or that,’ and we’ll discuss the problems and the good things,” he explained.
“He’s an experienced keeper too so it’s good to be able to talk things through and it’s a very healthy competition.
“At the end of the day both of us want to play but we will push each other on to be better.”
Wanderers are in the middle of a purple patch which has seen them score four goals in three consecutive away games for the first time in their history.
They have also scored four times in four of their last 10 games. Before Tuesday night, they had scored four in four of their previous 189 outings.
Those victories have ranged from the comprehensive, like Gillingham, to the dramatic, like Oxford and Fleetwood. But Alnwick feels momentum is now gathering behind the team as they look to bounce back to the Championship at the first time of asking.
“We know every game is going to need something different,” he said. “If we could turn up every week and win 4-0 it would be great. But in real life it doesn’t happen that way and you have to be ready to change your game-plan.
“Teams know we have been scoring goals and can set up to defend. It isn’t always easy to break them down.”
Alnwick has also been impressed with the return of Darren Pratley, even though the midfielder’s progress was checked by a hamstring injury in midweek.
“Having someone like him come in at this stage of the season has been fantastic, I don’t know where he has got his fitness from,” he added.
Wanderers go to relegation-threatened Shrewsbury Town on Saturday with Phil Parkinson considering changes after a draining week.
The likes of Tom Thorpe, Liam Trotter and Reece Wabara could be drafted into the squad to cover for injuries.
“We can’t sit back and pat ourselves on the back – we have to go at the weekend,” he said. “Three lads came down to Oxford but didn’t even get changed. I said to them it might well be their turn on Saturday.
“We have got a few niggles now but you cannot fault the spirit of this group of players.”
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